Moving Source from connect point to HostId in MulticastHandling

Change-Id: Ie8f678e150b7ee388680b8d8f27df0bce60ec01f
diff --git a/app/src/main/java/org/onosproject/segmentrouting/mcast/McastHandler.java b/app/src/main/java/org/onosproject/segmentrouting/mcast/McastHandler.java
index 3b659bd..289778e 100644
--- a/app/src/main/java/org/onosproject/segmentrouting/mcast/McastHandler.java
+++ b/app/src/main/java/org/onosproject/segmentrouting/mcast/McastHandler.java
@@ -183,7 +183,9 @@
         // Get source, mcast group
         // FIXME To be addressed with multiple sources support
         final ConnectPoint source = mcastPrevUpdate.sources()
+                .values()
                 .stream()
+                .flatMap(Collection::stream)
                 .findFirst()
                 .orElse(null);
         IpAddress mcastIp = mcastPrevUpdate.route().group();