bozo: fix typo in help text

Fix a typo for "interface" in the help text for bosserver.

Reviewed-on: http://gerrit.openafs.org/8144
Reviewed-by: Ken Dreyer <ktdreyer@ktdreyer.com>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jason Edgecombe <jason@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
(cherry picked from commit 58c089e642198a210462b3bf508056b56667f879)

Change-Id: I90fff6c691ae59ff467a641cb025cedc17a3bb4c
Reviewed-on: http://gerrit.openafs.org/9498
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>