修复bug，删除冗余

src/views/customer/AddCustomer.vue

@@ -514,7 +514,7 @@ export default {
                 });
             }
         },
-        async emailChange() { // 切换邮箱
+        emailChange() { // 切换邮箱
             let regex = /^([a-zA-Z]|[0-9])(\w|\-)+@[a-zA-Z0-9]+\.([a-zA-Z]{2,4})$/;
             if (regex.test(this.form.email)) {
                 let url = "";