Difficulty of Minesweeper can only be changed in standalone mode

[MollyMoriJing]

Describe the bug
Unable to change the game difficulty of Minesweeper in the inital size of window.

[Prozilla]

When reproducing this bug, I noticed the dropdown would briefly open and then disappear (less than a second). This is probably caused by some sort of duplicated click event in the WebView component.

[Prozilla]

@MollyMoriJing This bug has finally been fixed in 266cd6f.

I can't deploy right now due to this issue in gh-pages, but in the next deployment the fix will be live.