Bugfix [#37168] Outliner refresh error after removing constraints

Clear constraints operators were missing the NA_REMOVED flag which the Outliner
was checking for before it would perform the necessary updates.


git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk@61111 954f8c5b-7b00-dc11-b283-0030488c597c