Record answer SDP to recording metadata file

We record the answer SDP (not offer) to the metadata file, separeted by
newlines. It is after the PCAP file URL and before the timestamps. Maybe
we should be writing the rewritten SDP.

daemon/call_interfaces.c

@@ -693,6 +693,10 @@ static const char *call_offer_answer_ng(bencode_item_t *input, struct callmaster
 		if (recordcall.s) {
 			set_record_call(call, recordcall);
 		}
+		struct recording *recording = call->recording;
+		if (call->record_call && recording != NULL && recording->meta_fp != NULL) {
+			fprintf(recording->meta_fp, "\n%s\n", sdp.s);
+		}
 	}
 
 	bencode_dictionary_get_str(input, "metadata", &metadata);