contributors: only route with no parameters

[haarg]

Fixes #3212

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 73.21%. Comparing base (c788aa8) to head (34d5ee2).
Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3213      +/-   ##
==========================================
+ Coverage   73.13%   73.21%   +0.08%     
==========================================
  Files          69       69              
  Lines        2397     2397              
  Branches      338      338              
==========================================
+ Hits         1753     1755       +2     
+ Misses        516      515       -1     
+ Partials      128      127       -1     

Files with missing lines	Coverage Δ
lib/MetaCPAN/Web/Controller/About.pm	59.45% <ø> (ø)

... and 1 file with indirect coverage changes