Fix game window width/height setting being broken when using Arabic locale
Qt displays numbers differently in Arabic. The spinbox window height/width used
getText instead of value to get the value, which was wrong because this gets
the user-facing string (in arabic) instead of the number to use internally.
[patterns]
**.h = native
**.c = native
**.cpp = native
**.lua = native
**.txt = native
**.pas = native
**.inc = native
**.hs = native