message: Fix top alignment of PR sidebar in `clean-conversation-sidebar`
diff: }
  /* Align sidebar to the top */
  -.discussion-sidebar-item.rgh-clean-sidebar:first-child {
  - padding-top: 0;
  +.rgh-clean-sidebar .discussion-sidebar-item:first-child {
  + padding-top: 0 !important;
  }
  /* Move message under the `Unsubscribe` button above the button */
  