Add missing synchronized

Author: copierrj

deegree-core/deegree-core-workspace/src/main/java/org/deegree/workspace/graph/ResourceGraph.java

@@ -104,7 +104,7 @@ public synchronized <T extends Resource> ResourceNode<T> insertNode( ResourceMet
         return node;
     }
 
-    public <T extends Resource> void removeNode (ResourceIdentifier<T> id) {
+    public synchronized <T extends Resource> void removeNode (ResourceIdentifier<T> id) {
         nodeMap.remove( id );
         updateDependencies();
     }