free-game: jailbreak due to new OpenGLRaw version

This allows it to keep building after
ba5473676f867e32e9be5c2225ab4e8c8ded2be2 was pushed. Perhaps we should
add the extra OpenGL versions (2.9.1.0) and specify strict versions so
that it doesn't fail to build in 2 weeks.
cabal-install: update to version 1.20.0.2