SEBA-420 remove superfluous xproto options

Change-Id: Ib40f61f1e51b21b616dd8cf98c417f78cbbf24b9
diff --git a/Dockerfile.synchronizer b/Dockerfile.synchronizer
index 44276b1..d854f24 100644
--- a/Dockerfile.synchronizer
+++ b/Dockerfile.synchronizer
@@ -16,7 +16,7 @@
 
 # xosproject/simpleexampleservice-synchronizer
 
-FROM xosproject/xos-synchronizer-base:2.2.5
+FROM xosproject/xos-synchronizer-base:2.2.18
 
 COPY xos/synchronizer /opt/xos/synchronizers/simpleexampleservice
 COPY VERSION /opt/xos/synchronizers/simpleexampleservice/