pam-krb5: Add no_warn dummy option

This is to avoid throwing unknown option errors for pam.d files that
should work for the Heimdal pam_krb5 and the MIT friendly pam-krb5.
This option will be removed when the pam.d files are cleaned up after
the removal of Heimdal.

Sponsored by: 		The FreeBSD Foundation

contrib/pam-krb5/module/internal.h

@@ -109,6 +109,7 @@ struct pam_config {
 
     /* The authentication context, which bundles together Kerberos data. */
     struct context *ctx;
+    bool no_warn;            /* XXX Dummy argument, remove when Heimdal is removed. */
 };
 
 /* Default to a hidden visibility for all internal functions. */

contrib/pam-krb5/module/options.c

@@ -52,6 +52,7 @@ static const struct option options[] = {
     { K(no_ccache),          false, BOOL   (false) },
     { K(no_prompt),          true,  BOOL   (false) },
     { K(no_update_user),     true,  BOOL   (false) },
+    { K(no_warn),	     true,  BOOL   (false) },
     { K(only_alt_auth),      true,  BOOL   (false) },
     { K(pkinit_anchors),     true,  STRING (NULL)  },
     { K(pkinit_prompt),      true,  BOOL   (false) },