Fix undefined description when display_label_popup=False

labelme/app.py

@@ -1349,6 +1349,7 @@ class MainWindow(QtWidgets.QMainWindow):
             text = items[0].data(Qt.UserRole)
         flags = {}
         group_id = None
+        description = ""
         if self._config["display_label_popup"] or not text:
             previous_text = self.labelDialog.edit.text()
             text, flags, group_id, description = self.labelDialog.popUp(text)