patch from Fuchs against deadlock,

see http://www.yacy-forum.de/viewtopic.php?p=28804#28804


git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@3122 6c8d7289-2bf4-0310-a012-ef5d649a1542

source/de/anomic/kelondro/kelondroTree.java

@@ -733,8 +733,10 @@ public class kelondroTree extends kelondroRecords implements kelondroIndex {
 	    }
  	}
         // move node to recycling queue
+        synchronized (this) {
             deleteNode(node.handle());
         }
+    }
 
     protected Node firstNode() throws IOException {
         Handle h = getHandle(root);