Fix a one-character typo. The effects of which were "Console"->"Ttys" menu

would not launch (and gave no error). This was easily diagnosed by running
`bsdconfig -d' as root and seeing the following error right after selecting
the "Ttys" sub-menu:

DEBUG: f_getvar: var=[text] value=[
Error: Expected at least 6 tokens for --menu, have 4.
Use --help to list options.] r=0

Typo was introduced by SVN r251361.

usr.sbin/bsdconfig/console/ttys

@@ -86,7 +86,7 @@ dialog_menu_main()
 		--cancel-label \"\$msg_cancel\"    \
 		--menu \"\$prompt\"                \
 		$height $width $rows               \
-		$menu_ist                          \
+		$menu_list                         \
 		2>&1 >&$DIALOG_TERMINAL_PASSTHRU_FD
 	)
 	local retval=$?