Add Antoine Quint to the list of committers
https://bugs.webkit.org/show_bug.cgi?id=108750

No review necessary.

* Scripts/webkitpy/common/config/committers.py:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@141707 268f45cc-cd09-0410-ab3c-d52691b4dbfc