Remove duplicated line in test/error_in_creator.

[mgautierfr]

Adding twice the same entry (metadata or not) will throw a exception. But we are testing async error here.
If the async error not thrown in time because the writer thread is "slow", we will not catch the async error in time and we will throw the "wrong" exception.

Should fix #775

[codecov]

Codecov Report

Patch and project coverage have no change.

Comparison is base (6e31b4b) 84.30% compared to head (2e300dd) 84.30%.

❗ Current head 2e300dd differs from pull request most recent head 5db399f. Consider uploading reports for the commit 5db399f to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #776   +/-   ##
=======================================
  Coverage   84.30%   84.30%           
=======================================
  Files         101      101           
  Lines        4627     4627           
  Branches     2004     2001    -3     
=======================================
  Hits         3901     3901           
  Misses        725      725           
  Partials        1        1           

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.

[veloman-yunkan]

I could have questioned why you chose to delete line 294 rather than line 293, but I won't :)