Fix missing angle zerolization when 2d stabilization is disabled.

Not sure how it wasn't noticed for so long, probably check happens
in callee as well, but better be safe than sorry here.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@56516 954f8c5b-7b00-dc11-b283-0030488c597c