SEBA-461 use config filename consistent with xos-migrate tool

Change-Id: I7f6d45b9c9455670d57cbadf0a9cefa08761c804
diff --git a/Dockerfile.synchronizer b/Dockerfile.synchronizer
index 0137f8b..3958e3b 100644
--- a/Dockerfile.synchronizer
+++ b/Dockerfile.synchronizer
@@ -14,7 +14,7 @@
 
 # xosproject/simpleexampleservice-synchronizer
 
-FROM xosproject/xos-synchronizer-base:2.1.38
+FROM xosproject/xos-synchronizer-base:2.1.44
 
 COPY xos/synchronizer /opt/xos/synchronizers/simpleexampleservice
 COPY VERSION /opt/xos/synchronizers/simpleexampleservice/