Allow the youtube-manual upload backend to modify videos

So we can modify youtube videos we manually uploaded.
If the video isn't actually ours, it will error when the modify is attempted which is ok.

cutter/cutter/main.py

@@ -930,6 +930,7 @@ def main(
 	for location, backend_config in config.items():
 		backend_type = backend_config.pop('type')
 		no_updater = backend_config.pop('no_updater', False)
+		no_uploader = backend_config.pop('no_uploader', False)
 		cut_type = backend_config.pop('cut_type', 'full')
 		if backend_type == 'youtube':
 			backend_type = Youtube
@@ -945,7 +946,8 @@ def main(
 			backend.encoding_settings = cut_type
 		elif cut_type != 'full':
 			raise ValueError("Unknown cut type: {!r}".format(cut_type))
-		upload_locations[location] = backend
+		if not no_uploader:
+			upload_locations[location] = backend
 		if backend.needs_transcode:
 			needs_transcode_check[location] = backend
 		if not no_updater:

docker-compose.jsonnet

@@ -133,6 +133,8 @@
     // Backup options for advanced use, if the smart cut breaks things.
     desertbus_slow: {type: "youtube", cut_type: "full"},
     desertbus_emergency: {type: "youtube", cut_type: "fast"},
+    // Non-uploading backend that lets us modify manually-updated youtube videos
+    "youtube-manual": {type: "youtube", no_uploader: true}.
   },
   default_location:: "desertbus",
   // archive location is the default location for archive events,