don't forget glewInit

Change-Id: Ifc1c995f50fe34dbb072345aab37190d3a57e074
Reviewed-on: https://gerrit.libreoffice.org/10094
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>
Tested-by: Tomaž Vajngerl <quikee@gmail.com>