Removed USE="svn_sources" when installing gcc-4.6.0.

This is no longer needed as we have an svn mirror in gcc.git.

BUG=none
TEST=none

Change-Id: I5fdaeb8ff4b6456128765f18c0da6f582b54a379
Reviewed-on: http://gerrit.chromium.org/gerrit/5352
Tested-by: asharif <asharif@chromium.org>
Reviewed-by: Raymes Khoury <raymes@chromium.org>
1 file changed