Update validate.js (#493)

Edit validate email for support all email language and prevent matching multiple @ signs:

litemall-admin/src/utils/validate.js

@@ -60,7 +60,7 @@ export function validAlphabets(str) {
  * @returns {Boolean}
  */
 export function validEmail(email) {
-  const reg = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/
+  const reg = /^[^\s@]+@[^\s@]+\.[^\s@]+$/
   return reg.test(email)
 }