Allow DMF to be disabled

Signed-off-by: Kai Zimmermann <kai.zimmermann@bosch-si.com>

hawkbit-core/src/main/java/org/eclipse/hawkbit/eventbus/DeadEventListener.java

@@ -10,6 +10,7 @@ package org.eclipse.hawkbit.eventbus;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Service;
 
 import com.google.common.eventbus.DeadEvent;
 import com.google.common.eventbus.Subscribe;
@@ -22,6 +23,7 @@ import com.google.common.eventbus.Subscribe;
  *
  */
 @EventSubscriber
+@Service
 public class DeadEventListener {
     private static final Logger LOG = LoggerFactory.getLogger(DeadEventListener.class);
 

hawkbit-core/src/main/java/org/eclipse/hawkbit/eventbus/EventSubscriber.java

@@ -14,8 +14,6 @@ import static java.lang.annotation.RetentionPolicy.RUNTIME;
 import java.lang.annotation.Retention;
 import java.lang.annotation.Target;
 
-import org.springframework.stereotype.Service;
-
 /**
  * Marks an class as an event subscriber to listen on event on the event bus
  * without explicit register this class to the event bus.
@@ -36,7 +34,6 @@ import org.springframework.stereotype.Service;
  */
 @Target({ TYPE })
 @Retention(RUNTIME)
-@Service
 public @interface EventSubscriber {
 
 }