fix database connection

Change-Id: Ib9079ff36b3004bb11aa2134fa8a09c40180fd23
diff --git a/xos/synchronizer/exampleservice_config b/xos/synchronizer/exampleservice_config
index 604def0..c52d2db 100644
--- a/xos/synchronizer/exampleservice_config
+++ b/xos/synchronizer/exampleservice_config
@@ -3,7 +3,7 @@
 name=xos
 user=postgres
 password=password
-host=localhost
+host=xos_db
 port=5432
 
 # Required by XOS