fix: 修复系统用户用户名禁用的问题

src/views/assets/SystemUser/SystemUserCreate/fields.js

@@ -36,6 +36,8 @@ function getFields() {
       if (form.username_same_with_user) {
         this.fieldsMeta.username.el.disabled = true
         form.username = ''
+      } else {
+        this.fieldsMeta.username.el.disabled = false
       }
     }
   }