Using replace instead install when there is already an intent

Fixes the problem of flows being left on the data plane

Change-Id: Iec3db8b460123f2744a57d8c08d14c8effe9ec34
diff --git a/core/net/src/main/java/org/onosproject/net/intent/impl/WithdrawCoordinating.java b/core/net/src/main/java/org/onosproject/net/intent/impl/WithdrawCoordinating.java
index bd94ed6..aa5e993 100644
--- a/core/net/src/main/java/org/onosproject/net/intent/impl/WithdrawCoordinating.java
+++ b/core/net/src/main/java/org/onosproject/net/intent/impl/WithdrawCoordinating.java
@@ -47,6 +47,7 @@
     @Override
     public Optional<IntentUpdate> execute() {
         try {
+            // Note: current.installables() are not null or empty due to createIntentUpdate check
             FlowRuleOperations flowRules = intentManager.uninstallCoordinate(current, pending);
             pending.setInstallables(current.installables());
             return Optional.of(new Withdrawing(intentManager, pending, flowRules));