### Please describe the problem.

subject

### What steps will reproduce the problem?

repo from http://datasets.datalad.org/workshops/nih-2017/ds000114/derivatives/freesurfer/

### What version of git-annex are you using? On what operating system?

6.20170525+gitge1cf095ae-1~ndall+1


### Please provide any additional information below.

[[!format sh """
[student3@helix freesurfer]$ 'git' '-c' 'receive.autogc=0' '-c' 'gc.auto=0' 'annex' 'get' '--debug' '--json' '--json-progress' 'sub-01/label/lh.aparc.a2009s.annot'
[2017-07-30 09:33:42.479678681] read: git ["--git-dir=.git","--work-tree=.","--literal-pathspecs","ls-files","--cached","-z","--","sub-01/label/lh.aparc.a2009s.annot"]
[2017-07-30 09:33:42.501443872] read: git ["--git-dir=.git","--work-tree=.","--literal-pathspecs","show-ref","git-annex"]
[2017-07-30 09:33:42.523673251] process done ExitSuccess
[2017-07-30 09:33:42.523765181] read: git ["--git-dir=.git","--work-tree=.","--literal-pathspecs","show-ref","--hash","refs/heads/git-annex"]
[2017-07-30 09:33:42.544559473] process done ExitSuccess
[2017-07-30 09:33:42.553475534] chat: git ["--git-dir=.git","--work-tree=.","--literal-pathspecs","cat-file","--batch"]
[2017-07-30 09:33:42.554641292] chat: git ["--git-dir=.git","--work-tree=.","--literal-pathspecs","cat-file","--batch-check=%(objectname) %(objecttype) %(objectsize)"]
[2017-07-30 09:33:42.591306199] call: curl ["-sS","-f","-L","-C","-","-#","-o","/scratch/nih-2017/ds000114/derivatives/freesurfer/.git/annex/tmp/MD5E-s831572--7437ad482af573329af54386a15007fe","https://dl.dropbox.com/s/85yms1fl56pq7io/lh.aparc.a2009s.annot?dl=0","--user-agent","git-annex/6.20170525+gitge1cf095ae-1~ndall+1"]
curl: (77) error setting certificate verify locations:
  CAfile: /etc/ssl/certs/ca-certificates.crt
  CApath: /etc/ssl/certs
[2017-07-30 09:33:42.693467186] process done ExitFailure 77
{"command":"get","wanted":[{"here":false,"uuid":"00000000-0000-0000-0000-000000000001","description":"web"},{"here":false,"uuid":"5e47b3f3-f09c-4969-8885-920a49ff8a45","description":"yoh@smaug:/mnt/btrfs/datasets/datalad/crawl/workshops/nih-workshop-2017/ds000114/derivatives/freesurfer"}],"note":"Try making some of these repositories available:\n\t00000000-0000-0000-0000-000000000001 -- web\n \t5e47b3f3-f09c-4969-8885-920a49ff8a45 -- yoh@smaug:/mnt/btrfs/datasets/datalad/crawl/workshops/nih-workshop-2017/ds000114/derivatives/freesurfer\n","skipped":[],"success":false,"key":"MD5E-s831572--7437ad482af573329af54386a15007fe","file":"sub-01/label/lh.aparc.a2009s.annot"}
git-annex: get: 1 failed
[student3@helix freesurfer]$ 'git' '-c' 'receive.autogc=0' '-c' 'gc.auto=0' 'annex' 'get' '--json' '--json-progress' 'sub-01/label/lh.aparc.a2009s.annot'
curl: (77) error setting certificate verify locations:
  CAfile: /etc/ssl/certs/ca-certificates.crt
  CApath: /etc/ssl/certs
{"command":"get","wanted":[{"here":false,"uuid":"00000000-0000-0000-0000-000000000001","description":"web"},{"here":false,"uuid":"5e47b3f3-f09c-4969-8885-920a49ff8a45","description":"yoh@smaug:/mnt/btrfs/datasets/datalad/crawl/workshops/nih-workshop-2017/ds000114/derivatives/freesurfer"}],"note":"Try making some of these repositories available:\n\t00000000-0000-0000-0000-000000000001 -- web\n \t5e47b3f3-f09c-4969-8885-920a49ff8a45 -- yoh@smaug:/mnt/btrfs/datasets/datalad/crawl/workshops/nih-workshop-2017/ds000114/derivatives/freesurfer\n","skipped":[],"success":false,"key":"MD5E-s831572--7437ad482af573329af54386a15007fe","file":"sub-01/label/lh.aparc.a2009s.annot"}
git-annex: get: 1 failed
                        
while works fine without:
                 
[student3@helix freesurfer]$ 'git' '-c' 'receive.autogc=0' '-c' 'gc.auto=0' 'annex' 'get'  'sub-01/label/lh.aparc.a2009s.annot'
get sub-01/label/lh.aparc.a2009s.annot (from web...)
/scratch/nih-2017/ds000114/ 100%[===========================================>] 812.08K  --.-KB/s    in 0.08s
2017-07-30 09:34:02 URL:https://dl.dropboxusercontent.com/s/85yms1fl56pq7io/lh.aparc.a2009s.annot?dl=0 [831572/831572] -> "/scratch/nih-2017/ds000114/derivatives/freesurfer/.git/annex/tmp/MD5E-s831572--7437ad482af573329af54386a15007fe" [1]  
(checksum...) 
(recording state in git...)

"""]]

[[!meta author=yoh]]