Revert back to actix 0.10

Until Actix Web 4, we need to use an older version of actix so that the
runtime's match up to version 1.

src/video.rs

@@ -67,7 +67,7 @@ pub async fn create_playlist(video_path: &str, playlist_file: &str) -> Result<Ch
 
     let start_time = std::time::Instant::now();
     loop {
-        actix::clock::sleep(std::time::Duration::from_secs(1)).await;
+        actix::clock::delay_for(std::time::Duration::from_secs(1)).await;
 
         if Path::new(playlist_file).exists()
             || std::time::Instant::now() - start_time > std::time::Duration::from_secs(5)