Fix broadcast message misalignment on login page

* Change margin-top from 50px to 40px on login-page-broadcast

Closes #49364

app/assets/stylesheets/pages/login.scss

@@ -237,7 +237,7 @@
     }
 
     .login-page-broadcast {
-      margin-top: 50px;
+      margin-top: 40px;
     }
 
     .navless-container {

changelogs/unreleased/49364-fix-broadcast-margin.yml

+---
+title: Fix misalignment of broadcast message on login page
+merge_request: 20794
+author: Robin Naundorf
+type: fixed