adds synchornized dumplog

source/net/yacy/search/query/AccessTracker.java

@@ -191,13 +191,17 @@ public class AccessTracker {
     public static void dumpLog() {
         lastLogDump = System.currentTimeMillis();
     	localCount += localSearches.size();
+    	synchronized (localSearches) {
     	    while (!localSearches.isEmpty()) {
                 addToDump(localSearches.removeFirst(), 0);
             }
+    	}
         remoteCount += remoteSearches.size();
+        synchronized (remoteSearches) {
             while (!remoteSearches.isEmpty()) {
                 addToDump(remoteSearches.removeFirst(), 0);
             }
+        }
         Thread t = new Thread("AccessTracker.dumpLog") {
             @Override
             public void run() {