For backwards compatibility.

Undo workaround from b3ec881b.

This reverts commit 8dab06a2.

Leo P. Singer authored Oct 22, 2018 and Leo P. Singer committed Oct 22, 2018

See https://github.com/astropy/astropy/issues/7943.

By default, `bayestar-realize-coincs` will rewrite `simulation_id`
values so that their integer values match the corresponding events'
`coinc_event_id` values. The option `--preserve-ids` switches back
to the old behavior of preserving the original `simulation_id`
values.

I am seeding the global random number generator with
`np.random.seed`. I want MCMC sampling to respect the state of
this random number generator.