Since jessie-backports repo is no longer maintained, repo URL need to
change to archive.debian.org, also need to specify
Acquire::Check-Valid-Until=false.
Signed-off-by: Takuya ASADA <syuu@scylladb.com>
Message-Id: <20190327120916.25036-1-syuu@scylladb.com>
d1b1a4134c