actually call moddata_free_client() :)

src/s_misc.c

@@ -563,6 +563,9 @@ static void exit_one_client(aClient *sptr, const char *comment)
 		 */
 		if (!MyConnect(sptr))
 			unrealdns_delreq_bycptr(sptr);
+		
+		/* Free module related data for this client */
+		moddata_free_client(sptr);
 	}
 
 	/* Remove sptr from the client list */