[CORD-1616] Supports PD by DHCP relay App

Change-Id: I9a23534023ca2847bd3f77a3f9ee2b468c5bb422
diff --git a/apps/dhcprelay/src/main/java/org/onosproject/dhcprelay/Dhcp4HandlerImpl.java b/apps/dhcprelay/src/main/java/org/onosproject/dhcprelay/Dhcp4HandlerImpl.java
index e1b3933..44653bd 100644
--- a/apps/dhcprelay/src/main/java/org/onosproject/dhcprelay/Dhcp4HandlerImpl.java
+++ b/apps/dhcprelay/src/main/java/org/onosproject/dhcprelay/Dhcp4HandlerImpl.java
@@ -1598,4 +1598,9 @@
             flowObjectiveService.apply(deviceId, fwd);
         });
     }
+
+    @Override
+    public void setDhcpFpmEnabled(Boolean enabled) {
+        // v4 does not use fpm. Do nothing.
+    }
 }