cameraview.py: Only add camera views if camera defined
cameraview.py: Only add camera views if camera defined

patmarion/director,openhumanoids/director,manuelli/director,mitdrc/director,mitdrc/director,openhumanoids/director,patmarion/director,manuelli/director,patmarion/director,mitdrc/director,manuelli/director,mitdrc/director,patmarion/director,openhumanoids/director,openhumanoids/director,manuelli/director,mitdrc/director,openhumanoids/director,manuelli/director,patmarion/director