TFS plugin configuration belongs under unclassified
root element
jenkins:
[...]
unclassified:
teampluginglobalconfig:
collectionConfigurations:
- collectionUrl: http://test.com
credentialsId: tfsCredentials
enableTeamPushTriggerForAllJobs: true
enableTeamStatusForAllJobs: true
#userAccountMapper:
configFolderPerNode: true
User account name mapping strategy is not yet supported