update composite blocking from deleted, not client

fixing bug by deferring the deletion and removal of the
deleted to the next event cycle had the side effect that
this now happens in the event cycle of the compositor
restart, which was deferred to avoid precisely that...

so the test is now moved to the removal of the deleted
which got an additional flag wasClient to avoid calling
this action for each and every tooltip (and might be usable
elsewise)


FIXED-IN: 4.11
REVIEW: 111204