Add URL_GPHOTO_GITHUB with gphoto github page
Add URL_GPHOTO_GITHUB with gphoto github page

gphoto/libgphoto2-python,gphoto/libgphoto2-sharp,gphoto/libgphoto2.OLDMIGRATION,gphoto/libgphoto2.OLDMIGRATION,gphoto/libgphoto2.OLDMIGRATION,gphoto/libgphoto2.OLDMIGRATION,gphoto/libgphoto2-sharp