Fix redirections on Windows

[Xmader]

Thank you for fixing Backport Open Redirect vulnerability, but it breaks on Windows machines.

path.normalize("/path/to/file") returns \path\to\file on Windows, and it doesn't work in browsers.

[codecov-io]

Codecov Report

Merging #261 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #261   +/-   ##
=======================================
  Coverage   75.26%   75.26%           
=======================================
  Files          11       11           
  Lines         558      558           
  Branches      128      128           
=======================================
  Hits          420      420           
  Misses         51       51           
  Partials       87       87

Impacted Files	Coverage Δ
lib/ecstatic.js	72.36% <ø> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update ae7a39b...4d75eef. Read the comment docs.

[Xmader]

#262

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 75.26%. Comparing base (ae7a39b) to head (4d75eef).
Report is 4 commits behind head on master.

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #261   +/-   ##
=======================================
  Coverage   75.26%   75.26%           
=======================================
  Files          11       11           
  Lines         558      558           
  Branches      128      128           
=======================================
  Hits          420      420           
  Misses         51       51           
  Partials       87       87           

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