I found that a new implementation of IFO guardian was bad.

It works well when ISS goes to DOWN before LSC_LOCK goes to DOWN as I have expected.
But it unnecessarily speaks during the LOCK acquisition.

When IFO guardian goes up from LOCKING to LOCKED, it speaks once the message which
should be heard in the case of going down from OBSERVING to LOCKED.

So it should be modified again in order to avoid confusing operators...

Because loading IFO guardians makes gap of science mode if it's loaded in OBSERVING,
we should load it when IFO is down.