fix MessageBoard test for null data

source/net/yacy/data/MessageBoard.java

@@ -106,11 +106,11 @@ public class MessageBoard {
 	    if (key.length() > categoryLength) key = key.substring(0, categoryLength);
 	    while (key.length() < categoryLength) key += "_";
 	    key += dateString() + snString();
-	    record.put("author", ((authorName == null) || (authorName.isEmpty())) ? authorName : "anonymous");
-	    record.put("recipient", ((recName == null) || (recName.isEmpty())) ? recName : "anonymous");
-	    record.put("ahash", (authorHash == null) ? authorHash : "");
-	    record.put("rhash", (recHash == null) ? recHash : "");
-	    record.put("subject", (subject == null) ? subject : "");
+	    record.put("author", ((authorName != null) && (!authorName.isEmpty())) ? authorName : "anonymous");
+	    record.put("recipient", ((recName != null) && (!recName.isEmpty())) ? recName : "anonymous");
+	    record.put("ahash", (authorHash != null) ? authorHash : "");
+	    record.put("rhash", (recHash != null) ? recHash : "");
+	    record.put("subject", (subject != null) ? subject : "");
             record.put("message", (message == null) ?  "" : Base64Order.enhancedCoder.encode(message));
             record.put("read", "false");
 	}