Two tests added, one in t/db_dependent/Circulation.t to catch the
initial setting of to_address at enqueue time and a second in
t/db_dependent/Letters.t to catch the correcting at send time.
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>