refactor if statement to ternary

priv/frontend/src/components/App.js

@@ -185,13 +185,10 @@ export default class App extends Component {
         <Service name={name} key={name} graph={graphs[name]} {...info}/>
       ))
 
-      let notice = null
       const down = allServices.filter(([, { status }]) => !status)
-
-      if (down.length !== 0) {
-        // a service is down :(
-        notice = <DegradedNotice services={objectFromEntries(down)}/>
-      }
+      const notice = down.length > 0
+        ? <DegradedNotice services={objectFromEntries(down)}/>
+        : null
 
       metrics = (
         <div className="services">