Do not enable light if atlas size is 0, closes #9335

drivers/gles3/rasterizer_scene_gles3.cpp

@@ -4282,7 +4282,7 @@ void RasterizerSceneGLES3::render_scene(const Transform &p_cam_transform, const
 			if (i > 0) {
 				glEnable(GL_BLEND);
 			}
-			_setup_directional_light(i, p_cam_transform.affine_inverse(), shadow_atlas != NULL);
+			_setup_directional_light(i, p_cam_transform.affine_inverse(), shadow_atlas != NULL && shadow_atlas->size > 0);
 			_render_list(render_list.elements, render_list.element_count, p_cam_transform, p_cam_projection, env_radiance_tex, false, false, false, i > 0, shadow_atlas != NULL);
 		}
 	}
@@ -4345,7 +4345,7 @@ void RasterizerSceneGLES3::render_scene(const Transform &p_cam_transform, const
 	} else {
 		for (int i = 0; i < state.directional_light_count; i++) {
 			directional_light = directional_lights[i];
-			_setup_directional_light(i, p_cam_transform.affine_inverse(), shadow_atlas != NULL);
+			_setup_directional_light(i, p_cam_transform.affine_inverse(), shadow_atlas != NULL && shadow_atlas->size > 0);
 			_render_list(&render_list.elements[render_list.max_elements - render_list.alpha_element_count], render_list.alpha_element_count, p_cam_transform, p_cam_projection, env_radiance_tex, false, true, false, i > 0, shadow_atlas != NULL);
 		}
 	}