strongswan: use procd running check

strongswan: use procd running check

Instead of using the standard procd check, the function is overridden, and
the check to see if the service is running is performed using the command
'swanctl --stats > /dev/null 2>&1'. The problem with this is, that this
call is blocking if the strongswan charon socket is not available. The call
does not  return until the timeout has expired.

This block does not occur if we use the standard behavior of procd, which
checks whether the service it started is actually running. This change
therefore uses the standard call via procd, which returns the value without
blocking.

Signed-off-by: Florian Eckert <redacted>