OPENAFS-SA-2018-001 backup: use authenticated connection to butc
Use the standard routine to pick a client security object, instead of
always assuming rxnull. Respect -localauth as well as being able to
use the current user's tokens, but also provide a -nobutcauth argument
to fall back to the historical rxnull behavior (but only for the connections
to butc; vldb and budb connections are not affected).
(cherry picked from commit
345ee34236c08a0a2fb3fff016edfa18c7af4b0a)
Change-Id: I1e5e0e38d4003020db5875609db08194f7684bb7
git://git.openafs.org / openafs.git / commit