libobs: Remove unused variable in obs_source

libobs/obs-internal.h

@@ -756,7 +756,6 @@ struct obs_source {
 	volatile bool timing_set;
 	volatile uint64_t timing_adjust;
 	uint64_t resample_offset;
-	uint64_t last_audio_ts;
 	uint64_t next_audio_ts_min;
 	uint64_t next_audio_sys_ts_min;
 	uint64_t last_frame_ts;

libobs/obs-source.c

@@ -1576,7 +1576,6 @@ static void source_output_audio_data(obs_source_t *source,
 		}
 	}
 
-	source->last_audio_ts = in.timestamp;
 	source->next_audio_ts_min =
 		in.timestamp + conv_frames_to_time(sample_rate, in.frames);