Fix rest-server tests

[fd0]

Since today, the rest-server needs to be explicitly told (via --no-auth) that authentication is not necessary.

[codecov-io]

Codecov Report

Merging #1684 into master will increase coverage by 0.04%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1684      +/-   ##
==========================================
+ Coverage   52.14%   52.18%   +0.04%     
==========================================
  Files         143      143              
  Lines       11394    11394              
==========================================
+ Hits         5941     5946       +5     
+ Misses       4534     4529       -5     
  Partials      919      919

Impacted Files	Coverage Δ
internal/archiver/archiver.go	64.04% <0%> (-0.22%)	⬇️
internal/backend/s3/s3.go	63.07% <0%> (+2.3%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 0e0fee9...e5c929b. Read the comment docs.