Catch empty bytes (#14521)

frigate/api/media.py

@@ -461,7 +461,7 @@ def recording_clip(
         ) as ffmpeg:
             while True:
                 data = ffmpeg.stdout.read(1024)
-                if data is not None:
+                if data is not None and len(data) > 0:
                     yield data
                 else:
                     if ffmpeg.returncode and ffmpeg.returncode != 0: