[ONOS-4612]Update SFC flows inline with the Official OVS NSH patch

Change-Id: If58517841096a939860d88aa78eca7cae46b9935
diff --git a/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/PortPairGroup.java b/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/PortPairGroup.java
index bdcfd1d..0114470 100644
--- a/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/PortPairGroup.java
+++ b/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/PortPairGroup.java
@@ -67,6 +67,11 @@
     void addLoad(PortPairId portPairId);
 
     /**
+     * Reset the load for all the port pairs in the group.
+     */
+    void resetLoad();
+
+    /**
      * Get the load on the given port pair id.
      *
      * @param portPairId port pair id