doc: Use proper markup for emphasis

Author: petere

doc/src/sgml/config.sgml

@@ -1182,7 +1182,7 @@ include_dir 'conf.d'
        <para>
         Sets whether GSSAPI delegation should be accepted from the client.
         The default is <literal>off</literal> meaning credentials from the client will
-        NOT be accepted.  Changing this to <literal>on</literal> will make the server
+        <emphasis>not</emphasis> be accepted.  Changing this to <literal>on</literal> will make the server
         accept credentials delegated to it from the client. This parameter can only be
         set in the <filename>postgresql.conf</filename> file or on the server command line.
        </para>