SEBA-457 Upgrade to xos-core 2.2.5

Change-Id: I95a9df94b74d8e268e311e2cefef5b2e2b87eca3
diff --git a/Dockerfile.synchronizer b/Dockerfile.synchronizer
index e26ec41..44276b1 100644
--- a/Dockerfile.synchronizer
+++ b/Dockerfile.synchronizer
@@ -16,7 +16,7 @@
 
 # xosproject/simpleexampleservice-synchronizer
 
-FROM xosproject/xos-synchronizer-base:2.2.1
+FROM xosproject/xos-synchronizer-base:2.2.5
 
 COPY xos/synchronizer /opt/xos/synchronizers/simpleexampleservice
 COPY VERSION /opt/xos/synchronizers/simpleexampleservice/