Use curl to download restic in CI script

3 jobs for master in 25 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build Src
passed #3560
build:src

00:00:15

 
  Build Pkg
failed #3561
build:pkg

00:00:09

 
  Upload
skipped #3562
upload:pkg
 
Name Stage Failure
failed
build:pkg Build Pkg There is an unknown failure, please try again
Reading package lists...
Building dependency tree...
Reading state information...
curl is already the newest version (7.52.1-5+deb9u6).
curl set to manually installed.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
$ ./install_restic_for_tests.sh
bunzip2: (stdin) is not a bzip2 file.
ERROR: Job failed: exit code 1