[Feature request] Fix bitstream timing info (when changing FPS) as a checkbox

[PRiiXX]

Hi there,
would it be possible to add a checkmark that does --fix-bitstream-timing-information when changing the framerate in the GUI?
Some players have issues when playing files that have a modified framerate set in the container, --fix-bitstream-timing-information takes care of that.
It should be optional though, so a simple checkbox would be the best I think!