Correct docs for "kdb5_util load" switches

Remove obsolete parenthetical statement in the description of the
"-update" switch to "kdb5_util load".  Using the "-update" flag to
load a second dump made using the "-ov" switch is no longer necessary
now that the "-r13" format is the default.  Add statement that the
"-b7" dump format was the default for versions prior to 1.2.2 (to
match the statement from "dump" section).

[tlyu@mit.edu: commit message]

(cherry picked from commit 2d0f2fa)

ticket: 8085 (new)
version_fixed: 1.11.6
status: resolved

doc/admin/admin_commands/kdb5_util.rst

@@ -220,7 +220,8 @@ Options:
 
 **-b7**
     requires the database to be in the Kerberos 5 Beta 7 format
-    ("kdb5_util load_dump version 4").
+    ("kdb5_util load_dump version 4").  This was the dump format
+    produced on releases prior to 1.2.2.
 
 **-ov**
     requires the database to be in "ovsec_adm_import" format.  Must be
@@ -248,10 +249,7 @@ Options:
 
 **-update**
     records from the dump file are added to or updated in the existing
-    database.  (This is useful in conjunction with an ovsec_adm_export
-    format dump if you want to preserve per-principal policy
-    information, since the current default format does not contain
-    this data.)  Otherwise, a new database is created containing only
+    database.  Otherwise, a new database is created containing only
     what is in the dump file and the old one destroyed upon successful
     completion.