Fix issue with pam where it was looking for an sshd pam file instead of hpnsshd.

Mitch found this. Seems to have been cause by a change in OpenSSH 9.8 where
they made the pam service configurable and made the default sshd. This will
work in most situations because OpenSSH is already installed but will fail
if the only installed ssh server is hpn-ssh. This fix simply changes the default
name from 'sshd' to 'hpnsshd'.

Author: rapier1

servconf.c

@@ -71,7 +71,7 @@
 #include "sshbuf.h"
 
 #if !defined(SSHD_PAM_SERVICE)
-# define SSHD_PAM_SERVICE		"sshd"
+# define SSHD_PAM_SERVICE		"hpnsshd"
 #endif
 
 static void add_listen_addr(ServerOptions *, const char *,