bug#25688: services: ssh-daemon quits too early

[ng0 <contact.ng0@cryptolab.net>]

I have my openssh-service configured like this (not exactly, but it
serves an example well enough to not expose too much):

(service openssh-service-type
 (openssh-configuration
  (port-number 2200)
  (password-authentication? #t)
  (permit-root-login 'without-password)))

Now, when I reconfigure the system, ssh-daemon is started and I can ssh in.
When I reboot and try to ssh into the machine again, I see ssh-daemon is
stopped and I can't log in from a remote machine.

The issue seems to be that network-service is taking too long to come up
and therefore ssh-service is stopped at system boot similar to something
like this:

* starting ssh-daemon-service
* ssh-daemon depends on networking-service
* stopping ssh-daemon-service

some more services started, networking finally comes up while tor and
others have waited for networking to come up, but ssh-daemon is stopped
and doesn't wait for networking.

This system is currently on commit
883aab6462c49d4f4846a6f22168325e70227663

with no extra additions.
-- 
ng0 -- https://www.inventati.org/patternsinthechaos/