Large board sizes hit recursion limit

[s3bw]

Setting -x to 50 and -y to 50 with default mines causes python to hit a recursion limit. User suggests using deque instead.

https://www.reddit.com/r/Python/comments/ih8rt1/i_wrote_minesweeper_with_python/g2zikwl?utm_source=share&utm_medium=web2x&context=3