lt_LT locale: Update abbreviated month names (bug 22932).

A GNOME translator asked to use the same abbreviated month names
as provided by CLDR.  This sounds reasonable.  See the discussion:
https://bugzilla.gnome.org/show_bug.cgi?id=793645#c27



	[BZ #22932]
	* localedata/locales/lt_LT (abmon): Synchronize with CLDR.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 71d7b121)