soledad-server doesn't restart reliable on upgrade

[Varac]

Soledad-server was down on dev.pix today since 6:30 and it turned out that it wasn't restarted on upgrade of the package:

root@dev1:~# grep soledad-server /var/log/dpkg.log | tail -1
2016-06-23 06:31:31 status installed soledad-server:all 0.8.0~alpha~180.gbp9b3737
root@dev1:~# tail -1 /var/log/soledad.log.1
2016-06-23 06:31:26+0200 [-] Server Shut Down.

[Varac]

so the upgrade was this one:

2016-06-23 06:31:25 upgrade soledad-server:all 0.8.0~alpha~174.gbpa84123 0.8.0~alpha~180.gbp9b3737

I tried to reproduce it by installing ~174 and then upgrading to ~180, but i couldn't.

closing this until we encounter this again.