Move any code with youtube-dl access(which can be slow) to another thread. Fixes #2.

plasmoid/package/contents/ui/main.qml

@@ -95,6 +95,7 @@ Item {
                     var loadTrack = service.operationDescription("addURLToPlaylist");
                     loadTrack.URL = url.text;
                     service.startOperationCall(loadTrack);
+                    url.text = "";
                 }
             }
         }