Fixed a bug that phase 0 is not added to the insert statement

tripal_chado/includes/TripalImporter/GFF3Importer.inc

@@ -1231,7 +1231,7 @@ class GFF3Importer extends TripalImporter {
             'fmax' => $fmax,
             'strand' => $strand,
           );
-          if ($phase) {
+          if (isset($phase)) {
             $values['phase'] = $phase;
           }
           $result = chado_insert_record('tripal_gffcds_temp', $values);