Reject doesn't flush MPC

[drusk]

For the reals task, rejecting doesn't check whether it should flush the MPC lines it has buffered (it should be checking and flushing when the source is finished).

[ijiraq]

yes. just ran into that. We rejected all the observations of a particular source which then resulted in a zero length .mpc file. Interesting question of what to do when all source observations have been rejected. Just write out the mpc file for now.