Merge branch 'fix/bgp_groups_auth' into 'develop'

BGP group template: add authentication option

See merge request !164

geant/gap_ansible/roles/promote_p_to_pe/templates/routers/nokia/router/bgp_group.j2

@@ -2,6 +2,9 @@
                 <group alu:operation="replace">
                     <group-name>{{ group.name }}</group-name>
                     <admin-state>{{ group.admin_state | default('enable') }}</admin-state>
+                    {% if group.auth_key is defined %}
+                    <authentication-key>{{ group.auth_key }}</authentication-key>
+                    {% endif %}
                     {% if group.nhs is defined %}
                     <next-hop-self>{{ group.nhs }}</next-hop-self>
                     {% endif %}