#72691 default start time on reservation in past?

Instruments with 1 minute schedule rule were sometimes falling back to
:00 in the new reservation form when the next available reservation
time was not an increment of 5 minutes (e.g. 1:33 would get populated
in the form as 1:00)
Merge pull request #46 from tablexi/default_start_time_72691

#72691 default start time on reservation in past?