File download progress bar may not be muted.

[grouigrokon]

Whatever the log level, calling for the e3.net.http.download_files() method displays a progress bar,

I think that the progress bar should be displayed only when log level is INFO or higher (acknowledged there is a logger.info() call when the file is downloaded).

The e3.log.pretty_cli could be set/reset before and after the call to progress_bar (according to log level).