fix(react template): reverting bugfix + code clean-up

cmd/templates/create-react-app/frontend/package.json.template

@@ -19,7 +19,11 @@
     "extends": "react-app"
   },
   "browserslist": {
-    "production": [],
+    "production": [
+      ">0.2%",
+      "not dead",
+      "not op_mini all"
+    ],
     "development": [
       "last 1 chrome version",
       "last 1 firefox version",

cmd/templates/create-react-app/frontend/src/components/HelloWorld.js

@@ -26,22 +26,8 @@ class HelloWorld extends React.Component {
     this.setState({ showModal: false });
   }
 
-
-  startAsync() {
-    this.setState({
-      loading: true
-    });
-
-    window.backend.basic().then(result =>
-      this.setState({
-        loading: false,
-        result
-      })
-    );
-  }
-
   render() {
-    const { loading, result } = this.state;
+    const { result } = this.state;
     return (
       <div className="App">
         <button onClick={this.handleOpenModal} type="button">