Fix #5

Added a mutationobserverthing like in v3, this seems to fix the captcha not reloading

v3:
https://github.com/MayhemYDG/4chan-x/commit/825236a002f17d90ec44440ed66d47c1737deed7
https://github.com/MayhemYDG/4chan-x/issues/1524
Release 2.40.8