SEBA-457 Upgrade to xos-core 2.2.5

Change-Id: Ic4d088ecb1b134a9eca8b49b3501cc4142848895
diff --git a/Dockerfile.synchronizer b/Dockerfile.synchronizer
index 6584cd0..c38a7ac 100644
--- a/Dockerfile.synchronizer
+++ b/Dockerfile.synchronizer
@@ -16,7 +16,7 @@
 
 # xosproject/onos-synchronizer
 
-FROM xosproject/xos-synchronizer-base:2.2.1
+FROM xosproject/xos-synchronizer-base:2.2.5
 COPY xos/synchronizer /opt/xos/synchronizers/onos
 COPY VERSION /opt/xos/synchronizers/onos/