fix for timestamp being null

git-svn-id: svn+ssh://svn.internal.sanger.ac.uk/repos/svn/pathsoft/artemis/trunk@4304 ee4ac58c-ac51-4696-9907-e4b3aa274f04

uk/ac/sanger/artemis/util/DatabaseDocument.java

@@ -846,7 +846,7 @@ public class DatabaseDocument extends Document
   {
     Timestamp now = dao.getTimeLastModified(schema, uniquename);
     
-    if(now != null)
+    if(now != null && timestamp != null)
     {
       now.setNanos(0);
       timestamp.setNanos(0);