Improvement variable height in single column layout (#10917)

* Improvement variable height of compose and navigation panel in single column layout

* Fix wrong quotes and missing commas

app/javascript/mastodon/features/ui/components/compose_panel.js

@@ -9,9 +9,6 @@ const ComposePanel = () => (
     <SearchContainer openInRoute />
     <NavigationContainer />
     <ComposeFormContainer />
-
-    <div className='flex-spacer' />
-
     <LinkFooter withHotkeys />
   </div>
 );