MT#55283 check for NULL flags

Can be NULL for legacy protocols

Change-Id: I19ad39840060d7927b89f6ef7300f6df807915db
Warned-by: Coverity

daemon/call.c

@@ -2766,7 +2766,7 @@ int monologue_offer_answer(struct call_subscription *dialogue[2], GQueue *stream
 
 	__call_monologue_init_from_flags(other_ml, flags);
 
-	if (flags->exclude_recording) {
+	if (flags && flags->exclude_recording) {
 		monologue->no_recording = 1;
 		other_ml->no_recording = 1;
 	}