Update LDAP sync information message for linked groups

app/views/groups/group_members/_ldap_sync.html.haml

 - if current_user && @group.ldap_synced?
   .bs-callout.bs-callout-info
-    The members of this group are managed using LDAP and cannot be added, changed or removed here.
+    The members of this group are managed using LDAP and cannot be added or removed here.
     Because LDAP permissions in GitLab get updated one user at a time and because GitLab caches LDAP check results, changes on your LDAP server or in this group's LDAP sync settings may take up to #{Gitlab.config.ldap['sync_time']}s to show in the list below.
     %ul
       - @group.ldap_group_links.each do |ldap_group_link|