QtOpenGL: Adding workaround for undecodable string
QtOpenGL: Adding workaround for undecodable string

Based on @heinervdm's fix:
https://github.com/Ultimaker/Cura/issues/1117#issuecomment-259081608

Fixes: https://github.com/Ultimaker/Cura/issues/1117
Fixes: https://github.com/thopiekar/Cura-packaging/issues/12
onitake/Uranium,onitake/Uranium