Append to ghost log if exist
Append to ghost log if exist

Always try to append to ghost logs, this addresses issues like
restarting the instance and forever failing to start due to existing log files.

Signed-off-by: Adam Stokes <49c255c1d074742f60d19fdba5e2aa5a34add567@users.noreply.github.com>

battlemidget/juju-charm-ghost,battlemidget/juju-charm-ghost