Update VERSION and XOS parent container

Change-Id: I918a1b7f9f60d119590fe1ec0bcff849304eca8a
diff --git a/Dockerfile.synchronizer b/Dockerfile.synchronizer
index 9998917..316f548 100644
--- a/Dockerfile.synchronizer
+++ b/Dockerfile.synchronizer
@@ -14,7 +14,7 @@
 
 # xosproject/addressmanager-synchronizer
 
-FROM xosproject/xos-synchronizer-base:2.0.0
+FROM xosproject/xos-synchronizer-base:2.1.9
 
 COPY xos/synchronizer /opt/xos/synchronizers/addressmanager
 COPY VERSION /opt/xos/synchronizers/addressmanager/