krb5 commit [krb5-1.17]: Document default realm for krb5kdc

https://github.com/krb5/krb5/commit/bd546d70f7ab2f2e643225e9cb2124cca2ef5644
commit bd546d70f7ab2f2e643225e9cb2124cca2ef5644
Author: Greg Hudson <[email protected]>
Date:   Tue Apr 16 11:11:19 2019 -0400

    Document default realm for krb5kdc
    
    Document that if no krb5kdc -r option is specified, the default realm
    is served.
    
    (cherry picked from commit e5f866de8f47b91f609a6bab0d0e002f1a826222)
    
    ticket: 8796
    version_fixed: 1.17.1

 doc/admin/admin_commands/krb5kdc.rst |    4 +++-
 src/man/krb5kdc.man                  |    6 ++++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/doc/admin/admin_commands/krb5kdc.rst b/doc/admin/admin_commands/krb5kdc.rst
index 0342d0d..a661ec4 100644
--- a/doc/admin/admin_commands/krb5kdc.rst
+++ b/doc/admin/admin_commands/krb5kdc.rst
@@ -31,7 +31,9 @@ OPTIONS
 -------
 
 The **-r** *realm* option specifies the realm for which the server
-should provide service.
+should provide service.  This option may be specified multiple times
+to serve multiple realms.  If no **-r** option is given, the default
+realm (as specified in :ref:`krb5.conf(5)`) will be served.
 
 The **-d** *dbname* option specifies the name under which the
 principal database can be found.  This option does not apply to the
diff --git a/src/man/krb5kdc.man b/src/man/krb5kdc.man
index 8ace966..dfb9a14 100644
--- a/src/man/krb5kdc.man
+++ b/src/man/krb5kdc.man
@@ -1,6 +1,6 @@
 .\" Man page generated from reStructuredText.
 .
-.TH "KRB5KDC" "8" " " "1.17" "MIT Kerberos"
+.TH "KRB5KDC" "8" " " "1.18" "MIT Kerberos"
 .SH NAME
 krb5kdc \- Kerberos V5 KDC
 .
@@ -51,7 +51,9 @@ Distribution Center (AS/KDC).
 .SH OPTIONS
 .sp
 The \fB\-r\fP \fIrealm\fP option specifies the realm for which the server
-should provide service.
+should provide service.  This option may be specified multiple times
+to serve multiple realms.  If no \fB\-r\fP option is given, the default
+realm (as specified in krb5.conf(5)) will be served.
 .sp
 The \fB\-d\fP \fIdbname\fP option specifies the name under which the
 principal database can be found.  This option does not apply to the