Adding accessor.endpoint to synchronizers config schema

Change-Id: Ib02579cd12e2df3b19a6515b79c93bfeb85fd194
diff --git a/lib/xos-config/xosconfig/synchronizer-config-schema.yaml b/lib/xos-config/xosconfig/synchronizer-config-schema.yaml
index f41c7b2..6009501 100644
--- a/lib/xos-config/xosconfig/synchronizer-config-schema.yaml
+++ b/lib/xos-config/xosconfig/synchronizer-config-schema.yaml
@@ -26,6 +26,8 @@
     type: map
     required: True
     map:
+      endpoint:
+        type: str
       username:
         type: str
         required: True