Fix compilation with all features enabled
Fix compilation with all features enabled

tomaka/glium,caldwell/glium,bvssvni/glium,cpjreynolds/glium,sdotz/glium,glium/glium,christopheraugustus/glium,nicokoch/glium,TyOverby/glium,carbidegames/glium,binsoftware/glium,acolley/glium,msiglreith/glium,rozaliev/glium