update Web/src/components/sysDict/sysDict.vue.

fix:  全局系统字典组件 modelValue 未设置默认值导致的警告

Signed-off-by: xin12023 <chenxin2024@gmail.com>

Web/src/components/sysDict/sysDict.vue

@@ -8,6 +8,7 @@ const dictList = useUserInfo().dictList;
 const props = defineProps({
 	modelValue: {
 		type: [String, Number, Boolean, null],
+        default: null,
 		required: true,
 	},
 	code: {