Unbind pixmap from context when it is destroyed - fixes crash under xfvb.
Unbind pixmap from context when it is destroyed - fixes crash under xfvb.

nox/skia,larsbergstrom/skia,akiss77/skia,mmatyas/skia,akiss77/skia,mmatyas/skia,akiss77/skia,nox/skia,larsbergstrom/skia,larsbergstrom/skia,larsbergstrom/skia,nox/skia,vvuk/skia,vvuk/skia,akiss77/skia,mmatyas/skia,mmatyas/skia,vvuk/skia,nox/skia,vvuk/skia,vvuk/skia,mmatyas/skia,larsbergstrom/skia,mmatyas/skia,akiss77/skia,vvuk/skia,mmatyas/skia,akiss77/skia,mmatyas/skia,larsbergstrom/skia,nox/skia,akiss77/skia,akiss77/skia,larsbergstrom/skia,nox/skia,larsbergstrom/skia,larsbergstrom/skia,akiss77/skia,vvuk/skia,vvuk/skia,nox/skia,mmatyas/skia,nox/skia,vvuk/skia,nox/skia