Enable the ThreadPool when TUBESYNC_WORKERS is used

tubesync/tubesync/local_settings.py.container

@@ -62,6 +62,8 @@ else:
 
 DEFAULT_THREADS = 1
 BACKGROUND_TASK_ASYNC_THREADS = getenv('TUBESYNC_WORKERS', DEFAULT_THREADS, integer=True)
+if BACKGROUND_TASK_ASYNC_THREADS > 1:
+    BACKGROUND_TASK_RUN_ASYNC = True
 
 
 MEDIA_ROOT = CONFIG_BASE_DIR / 'media'