邮箱验证码改为纯小写字母

normandcrm/service/backend/helpers/RandomHelper.php

@@ -22,7 +22,7 @@ class RandomHelper
             return "";
         }
 
-        $randomChar = ['0','1','2','3','4','5','6','7','8','9'];
+        $randomChar = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'];
         $stringBuffer = '';
         for ($i = 0; $i < $length; $i++) {
             $stringBuffer .= $randomChar[abs(rand()) % count($randomChar)];