SEBA-420 remove superfluous xproto options

Change-Id: Ic928720d929f199a059385653baeb9ed32870723
diff --git a/Dockerfile.synchronizer b/Dockerfile.synchronizer
index 456c595..b8a9b43 100644
--- a/Dockerfile.synchronizer
+++ b/Dockerfile.synchronizer
@@ -16,7 +16,7 @@
 
 # xosproject/volt-synchronizer
 
-FROM xosproject/xos-synchronizer-base:2.2.5
+FROM xosproject/xos-synchronizer-base:2.2.18
 
 COPY xos/synchronizer /opt/xos/synchronizers/volt
 COPY VERSION /opt/xos/synchronizers/volt/