ControlledDynamicWebAppCluster: improve synchronization

Synchronising on these getters is not necessary, because the
values are set in init().
diff --git a/software/webapp/src/main/java/org/apache/brooklyn/entity/webapp/ControlledDynamicWebAppClusterImpl.java b/software/webapp/src/main/java/org/apache/brooklyn/entity/webapp/ControlledDynamicWebAppClusterImpl.java
index 8c52746..6ac61ce 100644
--- a/software/webapp/src/main/java/org/apache/brooklyn/entity/webapp/ControlledDynamicWebAppClusterImpl.java
+++ b/software/webapp/src/main/java/org/apache/brooklyn/entity/webapp/ControlledDynamicWebAppClusterImpl.java
@@ -184,13 +184,13 @@
 
     @SuppressWarnings("unchecked")
     @Override
-    public synchronized ConfigurableEntityFactory<WebAppService> getFactory() {
+    public ConfigurableEntityFactory<WebAppService> getFactory() {
         return (ConfigurableEntityFactory<WebAppService>) getAttribute(FACTORY);
     }
     
     // TODO convert to an entity reference which is serializable
     @Override
-    public synchronized DynamicWebAppCluster getCluster() {
+    public DynamicWebAppCluster getCluster() {
         return getAttribute(CLUSTER);
     }