Make tests for group membership more readable

roles/lmn_sssd/templates/sssd.conf.j2

@@ -17,6 +17,6 @@ ad_gpo_access_control = disabled
 ad_gpo_ignore_unreadable = True
 ad_maximum_machine_account_password_age = 0
 ignore_group_members = True
-{% if groups.localhome is defined and inventory_hostname in groups.localhome %}
+{% if 'localhome' in group_names %}
 override_homedir = /home/%u
 {% endif %}