Style: Fix whole-line commented code

They do not play well with clang-format which aligns the `//` part
with the rest of the code block, thus producing badly indented commented code.

scene/resources/default_theme/default_theme.cpp

@@ -125,7 +125,7 @@ static Ref<Texture> make_icon(T p_src) {
 
 static Ref<Shader> make_shader(const char*vertex_code,const char*fragment_code,const char*lighting_code) {
 	Ref<Shader> shader = (memnew( Shader(Shader::MODE_CANVAS_ITEM) ));
-//	shader->set_code(vertex_code, fragment_code, lighting_code);
+	//shader->set_code(vertex_code, fragment_code, lighting_code);
 
 	return shader;
 }