Address GitLab issue #399: ntpq config command is config-from-file

docs/includes/ntpq-body.txt

@@ -253,7 +253,7 @@ ind assid status conf reach auth condition last_event cnt
   Display a list of link:#clock[clock variables] for those associations
   supporting a reference clock.
 
-+config [...]+::
++:config [...]+::
   Send the remainder of the command line, including whitespace, to the
   server as a run-time configuration command in the same format as the
   configuration file. This command is experimental until further notice
@@ -551,8 +551,6 @@ by 'name', a shortname for the driver type.
 
 The -O (--old-rv) option of legacy versions has been retired.
 
-The command ":config" is no longer accepted; use "config" instead.
-
 == Known Limitations ==
 
 It is possible for a "config unpeer" command to fail silently, yielding