Make DAFS 'bos salvage' work in restricted mode

Make DAFS 'bos salvage' work in restricted mode

bosserver currently has code to specifically allow 'bos
salvage'-initiated salvages to run when in restricted mode. This only
specifically tests for running salvager, though, and so fails when 'bos
salvage' is run against a DAFS fileserver and tries to run
'salvageserver -client' instead.

Test for 'salvageserver -client' as well, so we can run 'bos salvage'
for DAFS fileservers in restricted mode.

Change-Id: I27052a440ea8d6347a9d86e4a1f1a7131a277b0b
Reviewed-on: http://gerrit.openafs.org/1048
Tested-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Derrick Brashear <shadow@dementia.org>