[build] Ensure that cogl-debug is disabled by default
[build] Ensure that cogl-debug is disabled by default

The new cogl-debug option was accidentally being enabled by default since
configure.ac checked the 'default_enable' variable not 'cogl_default_enable'

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