nonlatent workers do not have twistd log captured

on non-latent workers, twistd log is not captured in any way and cannot debug client-side problems.

Change: from standard output

application.setComponent(ILogObserver, FileLogObserver(sys.stdout).emit)

to standard twistd.log file

application.setComponent(ILogObserver, FileLogObserver(logfile).emit)

Already changed in:

• freebsd bbw1
• macos bbw1 and bbw2