Feature: sbd-inquisitor: SBD_DELAY_START can be configured with a delay value

SBD_DELAY_START now can also be enabled by being set to a specific delay
value, in seconds. Sometimes a longer delay than the default, "msgwait",
is needed, for example in the cases where it's considered to be safer to
wait longer than:

corosync token timeout + consensus timeout + pcmk_delay_max + msgwait

Be aware that the special value "1" means "yes" rather than "1s".