fix linebreaks in dynesty logging

Using dynesty through parallel_bilby, the logfile entries of the iter: 19 | bound: 0 | nc: 1 | ncall: type don't seem to have proper unix line-breaks, showing up as ^M in several tools including less and emacs, which is at least a mild annoyance when parsing them by eye or scripts.

I'm opening the issue here since @gregory.ashton mentioned this should be on the side of the main bilby package, not parallel.