add IOException

app/src/main/java/org/schabi/newpipe/player/PopupVideoPlayer.java

@@ -60,6 +60,8 @@ import org.schabi.newpipe.player.popup.PopupViewHolder;
 import org.schabi.newpipe.player.popup.StateInterface;
 import org.schabi.newpipe.util.NavStack;
 
+import java.io.IOException;
+
 public class PopupVideoPlayer extends Service implements StateInterface {
     private static final String TAG = ".PopupVideoPlayer";
     private static final boolean DEBUG = false;