patch from hint in

http://forum.yacy-websuche.de/viewtopic.php?p=26858#p26858
from gaston

htroot/yacy/transferRWI.java

@@ -216,9 +216,9 @@ public final class transferRWI {
             final Iterator<byte[]> bit = unknownURL.iterator();
             unknownURLs.ensureCapacity(unknownURL.size() * 25);
             while (bit.hasNext()) {
-                unknownURLs.append(",").append(UTF8.String(bit.next()));
+                unknownURLs.append(UTF8.String(bit.next())).append(',');
             }
-            if (unknownURLs.length() > 0) { unknownURLs.delete(0, 1); }
+            if (unknownURLs.length() > 0) { unknownURLs.setLength(unknownURLs.length() - 1); }
             if (wordhashes.isEmpty() || received == 0) {
                 sb.getLog().logInfo("Received 0 RWIs from " + otherPeerName + ", processed in " + (System.currentTimeMillis() - startProcess) + " milliseconds, requesting " + unknownURL.size() + " URLs, blocked " + blocked + " RWIs");
             } else {