Bug 1375198 - FreeBSD bootstrap: drop explicit dependency on libGL. r=rillian

libGL package was consolidated into mesa-libs but quarterly set still
uses the old name. Since gtk3 (via libepoxy) and gtk2 (via cairo)
already indirectly depend on mesa-libs take advantage of it to avoid
churn on updates.

MozReview-Commit-ID: F5LBOOthAMc

--HG--
extra : rebase_source : 4e3e30e817187c3ffef30e280554b12b02f44568

python/mozboot/mozboot/freebsd.py

@@ -36,7 +36,6 @@ class FreeBSDBootstrapper(BaseBootstrapper):
             'gconf2',
             'gtk2',
             'gtk3',
-            'libGL',
             'pulseaudio',
             'v4l_compat',
             'yasm',