Operoverride crash fix

Changes

@@ -871,3 +871,7 @@ Fixed stats being visible to users even after defining
 STATS_ONLYOPER in config.h
 --Luke
 ===================================
+
+Applied Syzop's fix for operoverride crash.
+--Luke
+===================================

src/channel.c

@@ -1214,7 +1214,7 @@ int  m_mode(cptr, sptr, parc, parv)
 	 * Now, we can actually do the mode.  */
 
 	(void)do_mode(chptr, cptr, sptr, parc - 2, parv + 2, sendts, 0);
-
+	opermode = 0;
 	return 0;
 }