Don't client_delete() on an Unmap event, only do that on a client delete event.
Don't client_delete() on an Unmap event, only do that on a client delete event.

found by (among others) todd@ when you have a lot of clients and do something
that maps and umaps a lot of windows fast.

Debugged with aid of gdb, todd, okan and NULL pointers in a pizza place in
edmonton while waiting an inordinately long time for food.

ok okan@, todd@

proger/cwm