In the latest stable version of SourceTree "refs/heads" is automatically added into command with push to remote and not switch off.
When I need push to gerrit so I need remote path without heads.

In version 2.4.0 it works.

new:
git -c diff.mnemonicprefix=false -c core.quotepath=false -c credential.helper=sourcetree push -v --tags origin refs/heads/refs/for/2.1:refs/heads/refs/for/2.1

old (required):
git -c diff.mnemonicprefix=false -c core.quotepath=false -c credential.helper=sourcetree push -v --tags origin refs/heads/2.1:refs/for/2.1