add radius template

geant/gap_ansible/roles/base_config/templates/routers/nokia/radius_auth.j2

+  <system>
+      <security>
+          <aaa 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">
+              <remote-servers alu:operation="replace">
+                  <radius>
+                      <authorization>true</authorization>
+                      {% for server in system_radius_servers %}
+                      <server>
+                          <index>{{loop.index0 + 1 }}</index>
+                          <address>{{ server.host }}</address>
+                          <secret>{{ server.nokia_secret }}</secret>
+                      </server>
+                      {% endfor %}
+                  </radius>
+              </remote-servers>
+          </aaa>
+      </security>
+  </system>