Re-enables multi-failure test case in round robin

[farazdagi]

What type of PR is this?

Other

What does this PR do? Why is it needed?

• There is a commented out test case in init-sync's round robin test file. I suppose there were some issues with multi-failure test case (it was commented out on previous implementation of syncing) - thus it was commented out.
• Our current implementation is capable of processing such multiple bad peers w/o any issues, so the case is re-enabled.

Which issues(s) does this PR fix?
N/A

Other notes for review

[codecov]

Codecov Report

Merging #6143 into master will decrease coverage by 0.20%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #6143      +/-   ##
==========================================
- Coverage   60.01%   59.80%   -0.21%     
==========================================
  Files         323      323              
  Lines       27674    27386     -288     
==========================================
- Hits        16608    16378     -230     
+ Misses       8817     8789      -28     
+ Partials     2249     2219      -30