jicofo: make sure client-proxy is properly configured

jicofo/rootfs/defaults/jicofo.conf

@@ -136,6 +136,7 @@ jicofo {
         username = "{{ .Env.JICOFO_AUTH_USER }}"
         password = "{{ .Env.JICOFO_AUTH_PASSWORD }}"  
         conference-muc-jid = "{{ .Env.XMPP_MUC_DOMAIN }}"
+        client-proxy = "focus.{{ .Env.XMPP_DOMAIN }}"
         disable-certificate-verification = true
       }
     }