Timed event "month days" value of 1 means "any day" (same as 0)

This field should not normally have a value of '1' (no way to configure that, normally, since days are numbered starting at 1 and bit 1 is 2), but if it does, it's treated the same as 0 (any day of the month) - so fix that mismatch in getnexteventtime(). Just noticed this while comparing the logic with the new is_time_to_run() functions in main.cpp. That logic wasn't (should not have) changed, so this mismatch in the treatment of mdays == 1 existed before.