#validate_if_empty_200 fixed validation for code 200 in response with empty body

[trumenov]

What does this PR do?

• Fixed bug when meilisearch server return in response code 200 and empty body without any taskUid.

Some times we detect error:
(Minitest::Result) [/home/runner/work/user/project/vendor/bundle/ruby/3.1.0/gems/meilisearch-0.22.0/lib/meilisearch/index.rb:80]:
NoMethodError: undefined method `[]' for nil:NilClass

This error we can not reproduce, it detected only in multithreading mode.

[DavertMik]

Hey, team! Could you check how ruby's client acts if Meilisearch returns an empty response with 200 code?
Because this happens to us sometimes.

This can be issue of meilisearch engine but error happens on the client
Instead of JSON it returns empty response

We use meilisearch 1.1.0, latest meilisearch-ruby and mailisearch-rails libs

This could have happened on previous versions of meilisearch / ruby client as we faced flakiness in our tests before.
This PR fixes this case and resolved flakiness for our tests which were executed in parallel mode

[brunoocasali]

Hi, @DavertMik can you give me some information about the method you used in your tests?

We use meilisearch 1.1.0, latest meilisearch-ruby and mailisearch-rails libs

Meilisearch is still in the v1.1 RCs. The latest version is v1.0.2. Does this issue happen in v1.0.2 as well?

Right now, I want to ensure this is a ruby/rails-only issue and discard any potential issue on the engine side.

[brunoocasali]

Hey @DavertMik and @trumenov, I would like you to try the new Meili versions, so we can ensure this is an SDK bug or a Meilisearch one!

Feel free to reopen!