Slava Kopchenin thanks for the output. Unfortunately, as noted in the earlier comment, the
argument is not workable in the git client plugin because the plugin must support git versions prior to git 2.
We can't abandon support for Red Hat 5, Red Hat 6, Debian 6, and several other working environments which provide git versions prior to git 2.
Your output is a good source to use to write a test to show the failure and then you could submit a pull request with the test and with code changes to resolve the failure. Even if all you do is write a test to show the failure and submit that as a pull request, that will help move towards an eventual fix for the bug.
I checked the %cI argument and it is definitely understood by git 2.6.0, but is not understood by git 2.1.4 (Ubuntu 14.04), git 1.9.1 (Debian 8), or git 1.7.1 (CentOS 6.7). Your sample is enough that I was able to create a failing test case to show the problem.