Bump uglify-js from 2.3.6 to 3.6.6
Bump uglify-js from 2.3.6 to 3.6.6

Bumps [uglify-js](https://github.com/mishoo/UglifyJS2) from 2.3.6 to 3.6.6.
- [Release notes](https://github.com/mishoo/UglifyJS2/releases)
- [Commits](https://github.com/mishoo/UglifyJS2/compare/v2.3.6...v3.6.6)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
mantoni/browser-reload,mantoni/browser-reload,mantoni/browser-reload