bug fix

src/modules/question/components/QuestionImportDialog.vue

@@ -203,7 +203,7 @@ export default {
 
       let formData = new FormData();
       Object.entries(this.modalForm).forEach(([key, val]) => {
-        formData.append(key, val);
+        if (val !== null) formData.append(key, val);
       });
       formData.append("file", this.fileData.file);