krb5 commit: Update SRV record documentation

https://github.com/krb5/krb5/commit/521175fd41f09d97d15d4d5a40b6611b81ef375f
commit 521175fd41f09d97d15d4d5a40b6611b81ef375f
Author: Greg Hudson <[email protected]>
Date:   Sun Sep 20 12:02:38 2020 -0400

    Update SRV record documentation
    
    The KDC has listened to TCP connections by default since commit
    8d88e2ab00be126237569dc72827ced2ce6b7d04 (ticket 6731).  Update the
    documentation for _kerberos._tcp accordingly.
    
    Correct a formatting error introduced by commit
    10eb93809b1af06e2b1147aee2e3e50058ba1bbd (ticket 8921).
    
    For _kpasswd._udp, if the _kerberos-adm._tcp fallback is used, the
    port number is changed to 464, not 749.
    
    Add entries for _kerberos-master._tcp and _kpasswd._tcp.
    
    ticket: 8948

 doc/admin/realm_config.rst |   23 +++++++++++++----------
 1 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/doc/admin/realm_config.rst b/doc/admin/realm_config.rst
index caacc70..35e4857 100644
--- a/doc/admin/realm_config.rst
+++ b/doc/admin/realm_config.rst
@@ -144,11 +144,9 @@ _kerberos._udp
     the most often.  Normally you should list port 88 on each of your
     KDCs.
 _kerberos._tcp
-    This is for contacting any KDC by TCP.  The MIT KDC by default
-    will not listen on any TCP ports, so unless you've changed the
-    configuration or you're running another KDC implementation, you
-    should leave this unspecified.  If you do enable TCP support,
-    normally you should use port 88.
+    This is for contacting any KDC by TCP.  Normally you should use
+    port 88.  This entry should be omitted if the KDC does not listen
+    on TCP ports, as was the default prior to release 1.13.
 _kerberos-master._udp
     This entry should refer to those KDCs, if any, that will
     immediately see password changes to the Kerberos database.  If a
@@ -163,11 +161,16 @@ _kerberos-master._udp
     not complete at this time, but it will eventually be used by the
     :ref:`kadmin(1)` program and related utilities.  For now, you will
     also need the **admin_server** variable in :ref:`krb5.conf(5)`.
-    _kpasswd._udp This should list port 464 on your primary KDC.  It
-    is used when a user changes her password.  If this entry is not
-    defined but a _kerberos-adm._tcp entry is defined, the client will
-    use the _kerberos-adm._tcp entry with the port number changed
-    to 749.
+_kerberos-master._tcp
+    The corresponding TCP port for _kerberos-master._udp, assuming the
+    primary KDC listens on a TCP port.
+_kpasswd._udp
+    This entry should list port 464 on your primary KDC.  It is used
+    when a user changes her password.  If this entry is not defined
+    but a _kerberos-adm._tcp entry is defined, the client will use the
+    _kerberos-adm._tcp entry with the port number changed to 464.
+_kpasswd._tcp
+    The corresponding TCP port for _kpasswd._udp.
 
 The DNS SRV specification requires that the hostnames listed be the
 canonical names, not aliases.  So, for example, you might include the