package/webkitgtk: security bump to version 2.30.5

package/webkitgtk: security bump to version 2.30.5

Fixes the following security issue:

- CVE-2020-13558: Processing maliciously crafted web content may lead to
  arbitrary code execution.  Description: A use after free issue in the
  AudioSourceProviderGStreamer class was addressed with improved memory
  management

For more details, see the advisory:
https://webkitgtk.org/security/WSA-2021-0001.html

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Acked-by: Adrian Perez de Castro <aperez@igalia.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>