[Glitch] Fix edge case where settings/admin page sidebar would be incorrectly hidden

Port 00b45b967e to glitch-soc

Signed-off-by: Claire <claire.github-309c@sitedethib.com>

app/javascript/flavours/glitch/styles/admin.scss

@@ -322,6 +322,10 @@ $content-width: 840px;
 
       & > ul {
         display: none;
+
+        &.visible {
+          display: block;
+        }
       }
 
       ul a,