remove Video document when removing video media, etc.

app/services/video.js

@@ -214,6 +214,7 @@ export default class VideoService extends SiteService {
     }
 
     await minioService.removeObject(video.media.bucket, video.media.key);
+    await Video.deleteOne({ _id: video._id });
   }
 
   async removeForUser (user) {