#1468 no 404 if missing favicon

[SabineMa]

#1445
avoid throwing a 404 if there is no favicon
avoid showing cached versions of favicon

[codecov]

Codecov Report

Attention: Patch coverage is 73.33333% with 4 lines in your changes missing coverage. Please review.

Project coverage is 51.82%. Comparing base (8d13c67) to head (88fc5c1).
Report is 12 commits behind head on master.

Files with missing lines	Patch %	Lines
...package/WAFaviconHandler.class/class/initialize.st	0.00%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1478      +/-   ##
==========================================
+ Coverage   51.78%   51.82%   +0.03%     
==========================================
  Files        9163     9154       -9     
  Lines       76738    76705      -33     
==========================================
+ Hits        39742    39753      +11     
+ Misses      36996    36952      -44     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[jbrichau]

Thanks!
It looks good. I would just want to see the 'categories.st' change reverted since it's reverting to an older format.