fix:下拉框选择bug修复

src/views/run/instant/instant.data.ts

@@ -111,7 +111,6 @@ export const searchFormSchema: FormSchema[] = [
     componentProps: ({ schema, tableAction, formActionType, formModel }) => {
       return {
       // xxxx props
-        allowClear: false,
         placeholder: '全部机组',
         options: optionList.units.map(unit => ({ value: unit.id, label: unit.name })),
         onChange: async (e: any) => {
@@ -144,7 +143,6 @@ export const searchFormSchema: FormSchema[] = [
     colProps: { span: 4 },
     componentProps: ({ formModel }) => {
       return {
-        allowClear: false,
         placeholder: '全部系统',
         options: optionList.types.map(type => ({ value: type.id, label: type.name })),
         onChange: async (e: any) => {
@@ -175,7 +173,6 @@ export const searchFormSchema: FormSchema[] = [
     colProps: { span: 4 },
     componentProps: () => {
       return {
-        allowClear: false,
         placeholder: '全部子系统',
         options: systemOptions.value.map(system => ({ value: system.id, label: system.name })),
       }