Bug 30523: Quiet console warning about missing shortcut-buttons map file

Bug 30523: Quiet console warning about missing shortcut-buttons map file

This patch updates the Flatpickr plugin shortcut-buttons which adds the
"Yesterday," "Today," and "Tomorrow" links to Flatpickr widgets.  This
updates it to the latest version, 0.4.0.

The file is modified in two ways: The version information is added to
the top of the file, and the sourceMappingURL line is removed from the
bottom. This quiets browser console warnings about a missing map file.

To test:
- apply the patch and clear your browser cache.
- Go to Circulation -> Check out and check out to a patron.
- Click "Checkout settings" and click the "Specify due date" field.
- In the pop-up calendar, test all controls, including the shortcut
  links, to confirm that everything works as before.
- In the browser console there should be no warning related to
  shortcut-buttons-flatpickr. (Firefox didn't have the warning, Chromium
  can be used.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>