c: fix #24 also for GLES not only GL
c: fix #24 also for GLES not only GL

hrehfeld/glad,QUSpilPrgm/glad,hrehfeld/glad,bsmr-opengl/glad,QUSpilPrgm/glad,0x1100/glad,hrehfeld/glad,QUSpilPrgm/glad,aaronmjacobs/glad,bsmr-opengl/glad,hrehfeld/glad,aaronmjacobs/glad,QUSpilPrgm/glad,bsmr-opengl/glad,aaronmjacobs/glad,aaronmjacobs/glad,0x1100/glad,bsmr-opengl/glad,0x1100/glad,0x1100/glad