SLING-5322 : made reference to SyncTokenService mandatory

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1715867 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/src/main/java/org/apache/sling/discovery/impl/TopologyWebConsolePlugin.java b/src/main/java/org/apache/sling/discovery/impl/TopologyWebConsolePlugin.java
index d99984d..e146e0c 100644
--- a/src/main/java/org/apache/sling/discovery/impl/TopologyWebConsolePlugin.java
+++ b/src/main/java/org/apache/sling/discovery/impl/TopologyWebConsolePlugin.java
@@ -107,7 +107,7 @@
     @Reference
     private ConnectorRegistry connectorRegistry;
 
-    @Reference(cardinality = ReferenceCardinality.OPTIONAL_UNARY)
+    @Reference
     private SyncTokenService syncTokenService;
 
     @Reference