workaround [#32866] Crash by cyclic use of Boolean Modifier

officially - modifiers shouldn't calc other objects derived mesh, but in some cases its needed at the moment for certain scenes, so just disallow booleans depending on booleans.


git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@54017 954f8c5b-7b00-dc11-b283-0030488c597c