[IRCServices] NickServ enforcer bug when unlinking nicknames

[Bergee]

	I recently experienced a minor bug on my network which is currently 
running IRCServices 5.0.31 on Red Hat Linux 9.0 on an Intel Celeron 1.7 
GHz processor.
	A while ago I noticed that a NickServ Enforcer bot had been sitting on 
a nickname for over an hour.  Checking NickServ INFO returned that the 
nickname was not registered.  After a little investigating in the log 
files I noticed that the nickname had very recently been unlinked by its 
owner.  With that in hand I've been able to consistently reproduce the 
problem by taking the following steps:  (This assumes of course that 
your network does not have NSForceNickChange enabled.)
	1) Register a nickname and enable automatic kill protection and then 
link another nickname to your name.
	2) Have another user use the nickname you just linked and wait for 
NickServ to kill the user.
	3) Unlink the other nickname from your main nickname and watch as the 
NickServ enforcer bot doesn't ever release the nickname.  If you attempt 
to use NickServ release you will be told the nickname isn't being held.
	Before reporting the problem, I upgraded to IRCServices 5.0.36 and it 
is still reproducible.  I believe that Services should simply remove the 
enforcer bot holding a nickname if the user unlinks the nickname while 
the enforcer is online.

Bergee