Added a fix in case the Target feature is also a feature in the GFF3 file but was introduced before the actual feature

tripal_chado/includes/TripalImporter/GFF3Importer.inc

@@ -2877,6 +2877,11 @@ class GFF3Importer extends TripalImporter {
         while (array_key_exists($temp_uname, $this->features));
         $uniquename = $temp_uname;
       }
+      // If this feature has already been added but as a target of a previous
+      // feature then we'll let it go through and replace the target feature.
+      elseif ($prev_feature['is_target'] == TRUE) {
+        // Do nothing.
+      }
       else {
         throw new Exception(t("A feature with the same ID exists multiple times: !uname", ['!uname' => $uniquename]));
       }