Merge pull request #2390 from int2001/clqrz_fix

Update NULLs at LoTW, too

application/models/Logbook_model.php

@@ -2725,7 +2725,7 @@ class Logbook_model extends CI_Model {
     $this->db->where('date_format(COL_TIME_ON, \'%Y-%m-%d %H:%i\') = "'.$datetime.'"');
     $this->db->where('COL_CALL', $callsign);
     $this->db->where('COL_BAND', $band);
-    $this->db->where('COL_LOTW_QSL_RCVD !=', $qsl_status);	// Prevent QSO from beeing updated twice (or more)
+    $this->db->where('ifnull(COL_LOTW_QSL_RCVD,\'\') !=', $qsl_status); // Prevent QSO from beeing updated twice (or more)
     $this->db->where('COL_STATION_CALLSIGN', $station_callsign);
 
     $this->db->update($this->config->item('table_name'), $data);