libobs: Remove unused wait_for_video flag

libobs/obs-internal.h

@@ -1246,9 +1246,7 @@ struct obs_encoder {
 
 	/* if a video encoder is paired with an audio encoder, make it start
 	 * up at the specific timestamp.  if this is the audio encoder,
-	 * wait_for_video makes it wait until it's ready to sync up with
-	 * video */
-	bool wait_for_video;
+	 * it waits until it's ready to sync up with video */
 	bool first_received;
 	struct obs_encoder *paired_encoder;
 	int64_t offset_usec;

libobs/obs-output.c

@@ -2402,8 +2402,6 @@ static inline void pair_encoders(obs_output_t *output)
 
 		if (!audio->active && !video->active &&
 		    !video->paired_encoder && !audio->paired_encoder) {
-
-			audio->wait_for_video = true;
 			audio->paired_encoder = video;
 			video->paired_encoder = audio;
 		}