Andrew Gregory authored Oct 06, 2014 and Allan McRae committed Oct 13, 2014

This prevents an exception in the event backup entries are not in the
correct format and brings the test in line with alpm's backup parsing
which splits on the last tab rather than the first.

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
Signed-off-by: Allan McRae <allan@archlinux.org>