first of all, don't worry as far as I think it's impossible for you (and for everybody else, right now) to commit anything into the main moodle git repository.
So, for sure you've committed it, yes, but in your own clone of the main repository. So I'd suggest you to do something like:
git log (to detect the commit you did, and copy its hash)
git diff xxxxxxxxxxxxx (to get the changes performed by that commit)
If your clone of the main repository is public (github...) then you can reference to it here (commit URL), else you'll need to attach here the results of the "git diff" command above.
Also, be noted above trying to keep the "official" branches of your repository (cvshead, MOODLE_19_STABLE...) clean for any change and, always, work in other branches. Else, if your change finally gets applied to moodle main repo, you can run under problems when you update your clone with changes already present there.
It's a bit different from what we have been using until now, but after playing with it a bit, you'll find it far better (and more powerful than CVS), as far as you can have any number of local branches for you, without interfering in the official ones and so on.
Hope this helps... I'm adding Sam here to look for your suggested change, in the mean time, just experiment with git and, don't worry, it's impossible to break anything in the main repo.
PS: Also, I think David Mudrak is working into one multi-level (from noob to ninja) course about git and Moodle. Perhaps you can be interested into play with it as tester / reviewer. Could be a good experiment. Feel free to ask him.