### Please describe the problem.
git-annex-move does not seem to be using parallelism.  i'm running
(master_env_py27_v28) [02:30 PM ~]$ ps -w -w -w -F 12231
UID        PID  PPID  C    SZ   RSS PSR STIME TTY      STAT   TIME CMD
ilya     12231 12230 99 271873062 1018700 26 14:15 pts/2 Sl+ 506:13 /data/vngs/viral-ngs-etc/mc3/envs/master_env_py27_v28/bin/git-annex move -J48 --all --to ilya-s3

and there is only one thread with git-annex.
 On what operating system?

git-annex version: 6.20180926-gc906aaf build flags: Assistant Webapp Pairing S3(multipartupload)(storageclasses) WebDAV Inotify ConcurrentOutput TorrentParser MagicMime Feed\ s Testsuite dependency versions: aws-0.17.1 bloomfilter-2.0.1.0 cryptonite-0.23 DAV-1.3.1 feed-0.3.12.0 ghc-8.0.2 http-client-0.5.7.0 persistent-s\ qlite-2.6.2 torrent-10000.1.1 uuid-1.3.13 yesod-1.4.5 key/value backends: SHA256E SHA256 SHA512E SHA512 SHA224E SHA224 SHA384E SHA384 SHA3_256E SHA3_256 SHA3_512E SHA3_512 SHA3_224E SHA3_2\ 24 SHA3_384E SHA3_384 SKEIN256E SKEIN256 SKEIN512E SKEIN512 BLAKE2B256E BLAKE2B256 BLAKE2B512E BLAKE2B512 BLAKE2B160E BLAKE2B160 BLAKE\ 2B224E BLAKE2B224 BLAKE2B384E BLAKE2B384 BLAKE2S256E BLAKE2S256 BLAKE2S160E BLAKE2S160 BLAKE2S224E BLAKE2S224 BLAKE2SP256E BLAKE2SP256\ BLAKE2SP224E BLAKE2SP224 SHA1E SHA1 MD5E MD5 WORM URL remote types: git gcrypt p2p S3 bup directory rsync web bittorrent webdav adb tahoe glacier ddar hook external operating system: linux x86_64 supported repository versions: 3 5 6 upgrade supported from repository versions: 0 1 2 3 4 5 local repository version: 5

(master_env_py27_v28) [01:05 PM /data/ilya-work]$ uname -a Linux ip-172-31-87-156 4.14.72-68.55.amzn1.x86_64 #1 SMP Fri Sep 28 21:14:54 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
