Remove "throws IOException" from ClusterCommunicationService APIs

that never throw IOExceptions. These APIs already return boolean to indicate
if sending failed.

Change-Id: I339949fe59f3b8b18a117aabc8d67402dc66c2a3
diff --git a/core/store/dist/src/main/java/org/onosproject/store/intent/impl/GossipIntentStore.java b/core/store/dist/src/main/java/org/onosproject/store/intent/impl/GossipIntentStore.java
index b7596dc..4ffd4bf 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/intent/impl/GossipIntentStore.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/intent/impl/GossipIntentStore.java
@@ -327,25 +327,14 @@
     }
 
     private void notifyPeers(InternalIntentEvent event) {
-        try {
-            broadcastMessage(INTENT_UPDATED_MSG, event);
-        } catch (IOException e) {
-            // TODO this won't happen; remove from API
-            log.debug("IOException broadcasting update", e);
-        }
+        broadcastMessage(INTENT_UPDATED_MSG, event);
     }
 
     private void notifyPeers(InternalSetInstallablesEvent event) {
-        try {
-            broadcastMessage(INTENT_SET_INSTALLABLES_MSG, event);
-        } catch (IOException e) {
-            // TODO this won't happen; remove from API
-            log.debug("IOException broadcasting update", e);
-        }
+        broadcastMessage(INTENT_SET_INSTALLABLES_MSG, event);
     }
 
-    private void broadcastMessage(MessageSubject subject, Object event) throws
-            IOException {
+    private void broadcastMessage(MessageSubject subject, Object event) {
         ClusterMessage message = new ClusterMessage(
                 clusterService.getLocalNode().id(),
                 subject,