feature：修复

src/views/secondaryMerchant/components/subMerchantForm.vue

@@ -15,6 +15,7 @@
                 <el-input v-if="isCustomer" v-model="formData.higherPrantNumber" disabled placeholder="系统自动生成" />
                 <el-select
                   v-else
+                  filterable
                   v-model="formData.higherPrantNumber"
                   placeholder="请选择"
                   clearable