[mingw-cross-compile.sh] Fix to use git rather than svn
[mingw-cross-compile.sh] Fix to use git rather than svn

The script includes a part to automatically checkout the Clutter
source and build it but it was using the old svn repo instead of git.

djdeath/clutter-android,Distrotech/clutter,nobled/clutter,jigpu/clutter,GNOME/clutter,jigpu/clutter,djdeath/clutter-multithreaded,spatulasnout/clutter,GNOME/clutter,rkudiyarov/clutter_osx,Distrotech/clutter,djdeath/clutter-android,GNOME/clutter,djdeath/clutter,ebassi/clutter,ebassi/clutter,djdeath/clutter-android,nobled/clutter,tardyp/clutter,heysion/clutter-clone,rkudiyarov/clutter_osx,Distrotech/clutter,GNOME/clutter,djdeath/clutter,collects/clutter,spatulasnout/clutter,dlespiau/clutter,nobled/clutter,ebassi/clutter,kerrickstaley/clutter-vala,dlespiau/clutter,heysion/clutter-clone,dlespiau/clutter,jigpu/clutter,jigpu/clutter,jigpu/clutter,heysion/clutter-clone,djdeath/clutter-multithreaded,Distrotech/clutter,spatulasnout/clutter,kerrickstaley/clutter-vala,heysion/clutter-clone,djdeath/clutter-multithreaded,djdeath/clutter,tardyp/clutter,collects/clutter,ebassi/clutter,kerrickstaley/clutter-vala,jigpu/clutter,collects/clutter,djdeath/clutter-android,rkudiyarov/clutter_osx,kerrickstaley/clutter-vala,GNOME/clutter,spatulasnout/clutter,djdeath/clutter,djdeath/clutter,spatulasnout/clutter,djdeath/clutter-android,rkudiyarov/clutter_osx,djdeath/clutter-multithreaded,Distrotech/clutter,collects/clutter,ebassi/clutter,Distrotech/clutter,heysion/clutter-clone,djdeath/clutter,tardyp/clutter,collects/clutter