修复bug

src/pages/exhibition/exhibitionEdit.vue

@@ -280,6 +280,7 @@ export default {
         endTime,
         thumb,
       };
+      if(this.form.type === "fixed") data.startTime=data.endTime=null
       data.content = this.editor.txt.html();
       let result = await this.$http({
         method: "post",