Surprisingly, Restart=always may not _always_ restart the unit if it restarts too fast.
Set a combination of options which should make systemd truly restart innernet always.
See https://unix.stackexchange.com/q/289629/352972.
The `RestartSec=60` is the main and important one which would prevent systemd from ever failing
to restart innernet in the default settings (because with it it would never exceed the default
limit of 5 restarts in 10 seconds).
`StartLimitIntervalSec=0` option is a complementary one for explicitly disabling the logic, and
may be removed from this PR if deemed unnecessary.
Matěj Laitl