update config dist file

config/redirects_www.example.com.json.dist

 {
     "comment": "Example redirect configuration file for domain.example.com",
     "direct":{
-        "mail": {"code": 301, "target": "https://www.example.com/mail" }
+        "/mail": {"code": 301, "target": "https://www.example.com/webmail" }
     },
     "regex":{
         ".*":   {"code": 307, "target": "https://www.example.com/" }