TWAMP light server - reflector replace

geant/gap_ansible/roles/iptrunk_twamp/templates/nokia/twamp_light_server.j2

@@ -4,7 +4,7 @@
         <router xmlns="urn:nokia.com:sros:ns:yang:sr:conf" xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0" xmlns:nokia-attr="urn:nokia.com:sros:ns:yang:sr:attributes">
             <router-name>Base</router-name>
               <twamp-light>
-                  <reflector>
+                  <reflector alu:operation="replace">
                       <admin-state>enable</admin-state>
                       <udp-port>{{ nokia_twamp_light.udp_port }}</udp-port>
                       <prefix>