Backport security fix from v5.2.1 to version-4 (non-Chromium browser dev-server vulnerability)#5534

Wajih-Ul-Hasan wants to merge 2 commits intowebpack:version-4webpack/webpack-dev-server:version-4from

Wajih-Ul-Hasan:patch-version-4Wajih-Ul-Hasan/webpack-dev-server:patch-version-4Copy head branch name to clipboard