Remove allow_token_displayname from docs as we don't support that any…

… longer

website/source/api/secret/pki/index.html.md

@@ -707,11 +707,6 @@ that is not allowed by the CN policy in the role, the request is denied.
   data. This does `not` include the common name in the CSR; use
   `use_csr_common_name` for that.
 
-- `allow_token_displayname` `(bool: false)` – If set, the display name of the
-  token used when requesting a certificate will be considered to be a valid host
-  name by the role. Normal verification behavior applies with respect to
-  subdomains and wildcards.
-
 - `ou` `(string: "")` – Specifies the OU (OrganizationalUnit) values in the
   subject field of issued certificates. This is a comma-separated string.