Apply the config after modifying it

Change-Id: I9c8ac36a16b3933bd7302d76ec4a301cf4b243a6
diff --git a/impl/src/main/java/org/onosproject/segmentrouting/cli/BlackHoleCommand.java b/impl/src/main/java/org/onosproject/segmentrouting/cli/BlackHoleCommand.java
index c45ff8e..88b7d4f 100644
--- a/impl/src/main/java/org/onosproject/segmentrouting/cli/BlackHoleCommand.java
+++ b/impl/src/main/java/org/onosproject/segmentrouting/cli/BlackHoleCommand.java
@@ -68,11 +68,13 @@
                 blackHoleIps = Sets.newConcurrentHashSet(appConfig.blackholeIPs());
                 blackHoleIps.add(IpPrefix.valueOf(prefix));
                 appConfig.setBalckholeIps(blackHoleIps);
+                appConfig.apply();
                 break;
             case "remove":
                 blackHoleIps = Sets.newConcurrentHashSet(appConfig.blackholeIPs());
                 blackHoleIps.remove(IpPrefix.valueOf(prefix));
                 appConfig.setBalckholeIps(blackHoleIps);
+                appConfig.apply();
                 break;
             default:
                 throw new UnsupportedOperationException("Unknown operation " + op);