pam_tacplus: Mention nss_tacplus in the manual page.

MFC after:	1 week
Sponsored by:	Klara, Inc.
Differential Revision:	https://reviews.freebsd.org/D40135

lib/libpam/modules/pam_tacplus/pam_tacplus.8

@@ -34,7 +34,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd August 2, 1999
+.Dd May 17, 2023
 .Dt PAM_TACPLUS 8
 .Os
 .Sh NAME
@@ -103,9 +103,10 @@ The standard TACACS+ client configuration file for
 .Nm
 .El
 .Sh SEE ALSO
+.Xr pam 3 ,
 .Xr passwd 5 ,
 .Xr tacplus.conf 5 ,
-.Xr pam 3
+.Xr nss_tacplus 8
 .Sh HISTORY
 The
 .Nm