In https://www.rfc-editor.org/rfc/rfc2831#section-2.1.2
digest-uri-value should be serv-type "/" host , where host is:
The DNS host name or IP address for the service requested. The
DNS host name must be the fully-qualified canonical name of the
host. The DNS host name is the preferred form; see notes on server
processing of the digest-uri.
Realm may not be the host, so we must specify the host explicitly.
Note this change only affects the non-SSPI digest code. The digest code
used by SSPI builds already uses the hostname to generate the spn.
Ref: https://github.com/curl/curl/issues/11369
Closes https://github.com/curl/curl/pull/11395
7703ca7f86