EOL Warnings fail download on FreeBSD 13

[gronke]

When fetching a FreeBSD 13 Release, the freebsd-update.sh file containing EOL warnings can no longer be downloaded from SVN.

libioc should download the file from the git mirror instead.

# ioc --log-level=spam fetch -r 13.0-RELEASE
[+] FetchRelease@13.0-RELEASE: already downloaded
Release was already downloaded. Skipping download.
[+] ReleaseConfiguration@13.0-RELEASE: SKIPPED [0.036s]
/etc/periodic.conf was read from /ioc/releases/13.0-RELEASE/root/etc/periodic.conf
Updated /etc/periodic.conf data from /ioc/releases/13.0-RELEASE/root/etc/periodic.conf
/etc/periodic.conf was not modified - skipping write
/etc/rc.conf was read from /ioc/releases/13.0-RELEASE/root/etc/rc.conf
Updated /etc/rc.conf data from /ioc/releases/13.0-RELEASE/root/etc/rc.conf
/etc/rc.conf was not modified - skipping write
/etc/sysctl.conf was read from /ioc/releases/13.0-RELEASE/root/etc/sysctl.conf
Updated /etc/sysctl.conf data from /ioc/releases/13.0-RELEASE/root/etc/sysctl.conf
/etc/sysctl.conf was not modified - skipping write
Re-using release snapshot 13.0-RELEASE@p0
[-] ReleaseUpdatePull@13.0-RELEASE: FAILED [0.156s]
Downloading update assets from https://svn.freebsd.org/base/release/13.0.0/usr.sbin/freebsd-update/freebsd-update.sh
Failed downloading EOL Warnings: 404
[+] ReleaseCopyBase@13.0-RELEASE: legacy basejal support disabled [0.0s]