Config menu does not draw correctly using Firefox

[jamiebegin]

This problem doesn't happen with the linuxserver Docker image of rutorrent.

[jamiebegin]

Actually, the whole web interface is jacked up under Firefox. Improperly sized icons, textboxes drawing over each other, obnoxious amounts of whitespace, etc.

[Jolly-Pirate]

Label scrolling is also buggy in Firefox/Waterfox Novik/ruTorrent#2389