No longer deconstructing account menu ref if it isn't rendered (#11585)

ui/components/app/account-menu/account-menu.component.js

@@ -253,12 +253,13 @@ export default class AccountMenu extends Component {
   }
 
   setShouldShowScrollButton = () => {
-    const { scrollTop, offsetHeight, scrollHeight } = this.accountsRef;
+    if (!this.accountsRef) {
+      return;
+    }
 
+    const { scrollTop, offsetHeight, scrollHeight } = this.accountsRef;
     const canScroll = scrollHeight > offsetHeight;
-
     const atAccountListBottom = scrollTop + offsetHeight >= scrollHeight;
-
     const shouldShowScrollButton = canScroll && !atAccountListBottom;
 
     this.setState({ shouldShowScrollButton });