package/webkitgtk: security bump to version 2.28.2

package/webkitgtk: security bump to version 2.28.2

This is a minor release which provides fixes for CVE-2020-11793,
CVE-2020-3887, CVE-2020-3894, and CVE-2020-3899.

Updating from 2.28.0 also brings a few rendering fixes, a build fix
on MIPS64, a build fix for GStreamer 1.12, and solves a couple of
crashes. The full release notes covering 2.28.1 and 2.28.2 can be
found at:

  https://webkitgtk.org/2020/04/13/webkitgtk2.28.1-released.html
  https://webkitgtk.org/2020/04/24/webkitgtk2.28.2-released.html

A detailed security advisory can be found at:

  https://webkitgtk.org/security/WSA-2020-0004.html

Note that the above does not cover all the CVEs, and a new advisory
including them is expected to be published in the next days.

Signed-off-by: Adrian Perez de Castro <aperez@igalia.com>
[yann.morin.1998@free.fr: two spaces in hash file]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>