d/control: depend on rsyslog

d/control: depend on rsyslog

required for our current tracking center implementation, a central
feature for PMG, which uses rsyslog log files and format.

Note that we evaluated switching to the journal there, but that was
deemed to be too slow (albeit could have only been start-up time
penalty) – anyhow, as of now this is a requirement to get the full
functionality, once the log-tracker can understand other formats in
an efficient way too we can add those as alternatives.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>