NITB: remove 'help' output about '-a' option that is removed for ages

This option was present in very early versions of the NITB, but
at least since 2011 it is no longer supported.  It's still listed
in --help output, which is wrong.

Change-Id: I1d2cceb588ec5fb34ec5e2c05a7d8c93310bee88
1 file changed