MT#60688 fix possible NULL dereference

Change-Id: I780b7034e5cbf5c1d8ddc53ee7f17975d5f3ebd7
Warned-by: Coverity

daemon/call.c

@@ -2848,7 +2848,7 @@ static void __media_init_from_flags(struct call_media *other_media, struct call_
 		if (!MEDIA_ISSET(other_media, PTIME_OVERRIDE))
 			other_media->ptime = sp->ptime;
 	}
-	if (sp->maxptime > 0) {
+	if (media && sp->maxptime > 0) {
 		media->maxptime = sp->maxptime;
 	}
 	if (media && flags->ptime > 0) {