Minor, removed MapDB shutdown hook because it's responsibility of the Moquette shutdown hook to teardown the storage

broker/src/main/java/org/dna/mqtt/moquette/messaging/spi/impl/SimpleMessaging.java

@@ -124,7 +124,10 @@ public class SimpleMessaging implements IMessaging, EventHandler<ValueEvent> {
         disruptorPublish(new StopEvent());
         try {
             //wait the callback notification from the protocol processor thread
+            LOG.debug("waiting 10 sec to m_stopLatch");
             boolean elapsed = !m_stopLatch.await(10, TimeUnit.SECONDS);
+            LOG.debug("after m_stopLatch");
+            m_executor.shutdown();
             if (elapsed) {
                 LOG.error("Can't stop the server in 10 seconds");
             }
@@ -181,9 +184,8 @@ public class SimpleMessaging implements IMessaging, EventHandler<ValueEvent> {
     private void processStop() {
         LOG.debug("processStop invoked");
         m_storageService.close();
-
 //        m_eventProcessor.halt();
-        m_executor.shutdown();
+//        m_executor.shutdown();
         
         subscriptions = null;
         m_stopLatch.countDown();

broker/src/main/java/org/dna/mqtt/moquette/messaging/spi/persistence/MapDBPersistentStore.java

@@ -65,7 +65,6 @@ public class MapDBPersistentStore implements IMessagesStore, ISessionsStore {
             throw new MQTTException("Can't create temp file for subscriptions storage [" + STORAGE_FILE_PATH + "]", ex);
         }
         m_db = DBMaker.newFileDB(tmpFile)
-                .closeOnJvmShutdown()
                 .make();
         m_retainedStore = m_db.getHashMap("retained");
         m_persistentMessageStore = m_db.getHashMap("persistedMessages");
@@ -219,9 +218,9 @@ public class MapDBPersistentStore implements IMessagesStore, ISessionsStore {
     }
 
     public void close() {
-        LOG.debug("closing disk storage");
         this.m_db.commit();
-//        this.m_db.close(); this is done by the Shutdown hook into MapDB
+        this.m_db.close();
+        LOG.debug("closed disk storage");
     }
 
     /*-------- QoS 2  storage management --------------*/