Unable to collect changes error on "git fetch"

We are running TeamCity 2018.1.2 on Windows 2012R2 with 16Gb RAM.
java version "1.8.0_181"
Java(TM) SE Runtime Environment (build 1.8.0_181-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.181-b13, mixed mode)

All build working with git repositories(tfsvc works well) failed with error:

Failed to collect changes, error: Error collecting changes for VCS repository 'http://tfs.cpr.ifx:8080/tfs/DefaultCollection/***/_git/***#refs/heads/master{instance id=2, parent internal id=1, parent id=id, description: "http://tfs.cpr.ifx:8080/tfs/DefaultCollection/***/_git/**#refs/heads/master"}'
'git fetch' command failed (repository dir: <TeamCity data dir>/system/caches/git/git-47580BB2.git).
stdout: Error occurred during initialization of VM
Could not reserve enough space for 1048576KB object heap
exit code: 1

I tried to set agent startup param in wrapper.conf:

wrapper.app.parameter.3=-Xmx2048m

but agent couldn't start with error:

INFO | jvm 1 | 2018/09/11 08:41:54 | Tue Sep 11 08:41:53 MSK 2018 ==> Start launch
INFO | jvm 1 | 2018/09/11 08:41:54 | Agent Java runtime version is 1.8
INFO | jvm 1 | 2018/09/11 08:41:54 | Launching agent with command: c:\TeamCity\jre\bin\java.exe -ea -Xmx2048m -XX:+HeapDumpOnOutOfMemoryError -Xrs -Dlog4j.configuration=file:../conf/teamcity-agent-log4j.xml -Dteamcity_logs=../logs/ -classpath C:\TeamCity\buildAgent\lib\agent-configurator.jar;C:\TeamCity\buildAgent\lib\agent-installer-ui.jar;C:\TeamCity\buildAgent\lib\agent-launcher.jar;C:\TeamCity\buildAgent\lib\agent-openapi.jar;C:\TeamCity\buildAgent\lib\agent-upgrade.jar;C:\TeamCity\buildAgent\lib\agent.jar;C:\TeamCity\buildAgent\lib\annotations.jar;C:\TeamCity\buildAgent\lib\app-wrapper.jar;C:\TeamCity\buildAgent\lib\buildAgent-updates-applying.jar;C:\TeamCity\buildAgent\lib\cloud-shared.jar;C:\TeamCity\buildAgent\lib\common-impl.jar;C:\TeamCity\buildAgent\lib\common-runtime.jar;C:\TeamCity\buildAgent\lib\common.jar;C:\TeamCity\buildAgent\lib\commons-beanutils-core.jar;C:\TeamCity\buildAgent\lib\commons-codec.jar;C:\TeamCity\buildAgent\lib\commons-collections-3.2.2.jar;C:\TeamCity\buildAgent\lib\commons-compress-1.9.jar;C:\TeamCity\buildAgent\lib\commons-httpclient-3.1.jar;C:\TeamCity\buildAgent\lib\commons-io-1.3.2.jar;C:\TeamCity\buildAgent\lib\commons-logging.jar;C:\TeamCity\buildAgent\lib\coverage-agent-common.jar;C:\TeamCity\buildAgent\lib\coverage-report.jar;C:\TeamCity\buildAgent\lib\duplicator-util.jar;C:\TeamCity\buildAgent\lib\ehcache-1.6.0-patch.jar;C:\TeamCity\buildAgent\lib\ehcache-1.7.2.jar;C:\TeamCity\buildAgent\lib\freemarker.jar;C:\TeamCity\buildAgent\lib\gson.jar;C:\TeamCity\buildAgent\lib\idea-settings.jar;C:\TeamCity\buildAgent\lib\inspections-util.jar;C:\TeamCity\buildAgent\lib\jaxen-1.1.1.jar;C:\TeamCity\buildAgent\lib\jdk-searcher.jar;C:\TeamCity\buildAgent\lib\jdom.jar;C:\TeamCity\buildAgent\lib\joda-time.jar;C:\TeamCity\buildAgent\lib\launcher-api.jar;C:\TeamCity\buildAgent\lib\launcher.jar;C:\TeamCity\buildAgent\lib\log4j-1.2.12-json-layout-1.0.9.jar;C:\TeamCity\buildAgent\lib\log4j-1.2.12.jar;C:\TeamCity\buildAgent\lib\messages.jar;C:\TeamCity\buildAgent\lib\nuget-utils.jar;C:\TeamCity\buildAgent\lib\openapi.jar;C:\TeamCity\buildAgent\lib\patches-impl.jar;C:\TeamCity\buildAgent\lib\patches.jar;C:\TeamCity\buildAgent\lib\processesTerminator.jar;C:\TeamCity\buildAgent\lib\resources_en.jar;C:\TeamCity\buildAgent\lib\runtime-util.jar;C:\TeamCity\buildAgent\lib\server-logging.jar;C:\TeamCity\buildAgent\lib\serviceMessages.jar;C:\TeamCity\buildAgent\lib\slf4j-api-1.7.5.jar;C:\TeamCity\buildAgent\lib\slf4j-log4j12-1.7.5.jar;C:\TeamCity\buildAgent\lib\spring-scripting\spring-scripting-bsh.jar;C:\TeamCity\buildAgent\lib\spring-scripting\spring-scripting-groovy.jar;C:\TeamCity\buildAgent\lib\spring-scripting\spring-scripting-jruby.jar;C:\TeamCity\buildAgent\lib\spring.jar;C:\TeamCity\buildAgent\lib\trove-3.0.3.jar;C:\TeamCity\buildAgent\lib\trove4j.jar;C:\TeamCity\buildAgent\lib\util.jar;C:\TeamCity\buildAgent\lib\xercesImpl.jar;C:\TeamCity\buildAgent\lib\xml-rpc-wrapper.jar;C:\TeamCity\buildAgent\lib\xmlrpc-2.0.1.jar;C:\TeamCity\buildAgent\lib\xpp3-1.1.4c.jar;C:\TeamCity\buildAgent\lib\xstream-1.4.10-custom.jar;C:\TeamCity\buildAgent\lib\xz-1.5.jar jetbrains.buildServer.agent.AgentMain -file ../conf/buildAgent.properties -launcher.version 58537
INFO | jvm 1 | 2018/09/11 08:41:54 | Error occurred during initialization of VM
INFO | jvm 1 | 2018/09/11 08:41:54 | Could not reserve enough space for 2097152KB object heap
INFO | jvm 1 | 2018/09/11 08:41:54 | Agent process finished
INFO | jvm 1 | 2018/09/11 08:41:54 | Agent has exited with code: 1