CORD-2772 set version number for vrouter service

Change-Id: I7bbf4150c7529e97c7d3a8c1571a50b456f27662
diff --git a/xos/synchronizer/Dockerfile.synchronizer b/xos/synchronizer/Dockerfile.synchronizer
index 108bd66..4adc789 100644
--- a/xos/synchronizer/Dockerfile.synchronizer
+++ b/xos/synchronizer/Dockerfile.synchronizer
@@ -13,6 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+# This Dockerfile is DEPRECATED and will be removed imminently.
 
 # xosproject/vrouter-synchronizer
 FROM xosproject/xos-synchronizer-base:candidate