Use strict dependency between metacity/libmetacity-private0a and

metacity-common to ensure we have the correct version of metacity-common
providing the org.gnome.metacity gsettings schema.

git-svn-id: svn://anonscm.debian.org/pkg-gnome/desktop/unstable/metacity@35176 db0db5de-e4c8-0310-9441-90abf70311f7