Middlewares should use errors.As() instead of type assertion on HTTPError

[danielbprice]

• Helps consumers who want to wrap HTTPError, and other use cases

[codecov]

Codecov Report

Merging #2227 (59a0dc9) into master (70acd57) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #2227   +/-   ##
=======================================
  Coverage   92.34%   92.34%           
=======================================
  Files          37       37           
  Lines        3122     3123    +1     
=======================================
+ Hits         2883     2884    +1     
  Misses        150      150           
  Partials       89       89           

Impacted Files	Coverage Δ
middleware/request_logger.go	97.61% <100.00%> (+0.02%)	⬆️
middleware/static.go	70.00% <100.00%> (ø)

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