Correct UnhookWindowsHook

["Medland, Bill" <Bill.Medland@accpac.com>]

Bill Medland (medbi01@accpac.com)
Correct UnhookWindowsHook.  Clear the handle so that the server
doesn't try to use it.

Index: wine/dlls/user/hook.c
===================================================================
RCS file: /home/wine/wine/dlls/user/hook.c,v
retrieving revision 1.2
diff -u -r1.2 hook.c
--- wine/dlls/user/hook.c	20 Nov 2002 19:54:32 -0000	1.2
+++ wine/dlls/user/hook.c	22 Nov 2002 23:05:50 -0000
@@ -363,6 +363,7 @@
 
     SERVER_START_REQ( remove_hook )
     {
+        req->handle = 0;
         req->id   = id;
         req->proc = proc;
         ret = !wine_server_call_err( req );