config-pull deletes .htaccess file

Apologies if this is a duplicate, I did search and the closest I could find is #1010 but I don't think it's relevant here.

When running `drush config-pull` the .htaccess file is removed.

Could a solution be to add an extra rsync option, say `exclude-htaccess` to `drush_config_pull()` in _config.drush.inc_ that is handled by `_drush_build_rsync_options()` in _rsync.core.inc_?
