Fix configuration placement

The code and the prose were misplaced.

mu4e/mu4e.texi

@@ -1664,15 +1664,15 @@ see @ref{Setting the default emacs mail program}.
 @item Normally, @t{mu4e} @emph{buries} the message buffer after sending; if you want
 to kill the buffer instead, add something like the following to your
 configuration:
+@lisp
+(setq message-kill-buffer-on-exit t)
+@end lisp
 @item If you want to exclude your own e-mail address when ``replying to
 all'', set @code{mu4e-compose-dont-reply-to-self} to @code{t}.  In order
 for this to work properly you need to properly set the
 @code{user-mail-address} variable or in the case you use multiple e-mail
 addresses you need to set the @code{mu4e-user-mail-address-list}
 variable accordingly.
-@lisp
-(setq message-kill-buffer-on-exit t)
-@end lisp
 @end itemize
 
 @node Searching