Prevent add shader uniform doc when DocTool is not inited

scene/resources/shader.cpp

@@ -173,7 +173,7 @@ void Shader::get_shader_uniform_list(List<PropertyInfo> *p_params, bool p_get_gr
 		}
 	}
 #ifdef TOOLS_ENABLED
-	if (Engine::get_singleton()->is_editor_hint() && !class_doc.name.is_empty() && p_params) {
+	if (EditorHelp::get_doc_data() != nullptr && Engine::get_singleton()->is_editor_hint() && !class_doc.name.is_empty() && p_params) {
 		EditorHelp::get_doc_data()->add_doc(class_doc);
 	}
 #endif