fix open redirect vulnerability with AddTrailingSlashWithConfig and RemoveTrailingSlashWithConfig

[aldas]

fix open redirect vulnerability with AddTrailingSlashWithConfig and RemoveTrailingSlashWithConfig (#1771)

[codecov]

Codecov Report

Merging #1775 (e3ef5ac) into master (932976d) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #1775      +/-   ##
==========================================
+ Coverage   89.74%   89.75%   +0.01%     
==========================================
  Files          32       32              
  Lines        2672     2675       +3     
==========================================
+ Hits         2398     2401       +3     
  Misses        175      175              
  Partials       99       99              

Impacted Files	Coverage Δ
middleware/slash.go	91.30% <100.00%> (+0.60%)	⬆️

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[lammel]

Great, we have even more table driven tests now.
Looks good! @aldas

[aldas]

it if is time to merge, please merge by squashing commits.