Retropie-setup: Look into sdl 2.0.5 issues with keyboard input on ES

[joolswills]

https://github.com/RetroPie/RetroPie-Setup/commit/aed35b727609a88aa4f6f29ee65815ca0188bce6#commitcomment-19909047

@joolswills rebuilding ES from source (while maintaining 2.0.5) did NOT fix the issues for me. The alphaneumeric stuff im typing is going to BASH not the text box. This seems limited to emulationstation as im not seeing this behaviour from other SDL2 apps im testing, Vice, fuse(sdl2 branch) , hatari 2.0

[joolswills]

It's this issue - https://bugzilla.libsdl.org/show_bug.cgi?id=3469

[joolswills]

This has been resolved upstream. We would need to backport it for 2.0.5 though, which I might do (or I could revert the original changeset in our 2.0.5)

[joolswills]

there was a large code reformat inbetween the original changeset that broke it and the 2.0.5 release, meaning some manual work to revert the original patch. The fix is a lot smaller, so that would be easier to backport.

[joolswills]

fix applied cleanly to 2.0.5 - will test and if all good, will update retropie sdl2 to 2.0.5 again.

[joolswills]

After 4 backported patches, keyboard input seems to be sorted, including the broken terminal on exit. Will rebuild sdl2.0.5 packages and then update retropie-setup.