package/vlc: security bump version to 3.0.8

package/vlc: security bump version to 3.0.8

Release notes: https://www.videolan.org/developers/vlc-branch/NEWS

Fixes the following security bugs:
 * Fix a buffer overflow in the MKV demuxer (CVE-2019-14970)
 * Fix a read buffer overflow in the avcodec decoder (CVE-2019-13962)
 * Fix a read buffer overflow in the FAAD decoder
 * Fix a read buffer overflow in the OGG demuxer (CVE-2019-14437, CVE-2019-14438)
 * Fix a read buffer overflow in the ASF demuxer (CVE-2019-14776)
 * Fix a use after free in the MKV demuxer (CVE-2019-14777, CVE-2019-14778)
 * Fix a use after free in the ASF demuxer (CVE-2019-14533)
 * Fix a couple of integer underflows in the MP4 demuxer (CVE-2019-13602)
 * Fix a null dereference in the dvdnav demuxer
 * Fix a null dereference in the ASF demuxer (CVE-2019-14534)
 * Fix a null dereference in the AVI demuxer
 * Fix a division by zero in the CAF demuxer (CVE-2019-14498)
 * Fix a division by zero in the ASF demuxer (CVE-2019-14535)

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>