Decrease min-height for Login Dropdown Menu

Fixes #2690

This is noticable when you have disabled local authentication, and only have a singular remote authentication such as Shibboleth or Orcid.

(cherry picked from commit 09fc44a)

src/app/shared/auth-nav-menu/auth-nav-menu.component.scss

@@ -4,7 +4,7 @@
 }
 
 .loginDropdownMenu {
-  min-height: 260px;
+  min-height: 75px;
 }
 
 .dropdown-item.active, .dropdown-item:active,