SEBA-420 remove superfluous xproto options

Change-Id: Ie9e5a2b72e9330effba358c2029a3a01bca83f40
diff --git a/Dockerfile.synchronizer b/Dockerfile.synchronizer
index c38a7ac..0b24cbf 100644
--- a/Dockerfile.synchronizer
+++ b/Dockerfile.synchronizer
@@ -16,7 +16,7 @@
 
 # xosproject/onos-synchronizer
 
-FROM xosproject/xos-synchronizer-base:2.2.5
+FROM xosproject/xos-synchronizer-base:2.2.18
 COPY xos/synchronizer /opt/xos/synchronizers/onos
 COPY VERSION /opt/xos/synchronizers/onos/