Fix dart.academy 404
Fix dart.academy 404

dart.academy no longer recognizes angular2 as a tag

This fixes one of the broken links reported in https://github.com/dart-lang/site-webdev/issues/1345

@kwalrath

Closes #1014

PiperOrigin-RevId: 187897880

angulardart/angular,kevmoo/angular,chalin/angular2,matanlurey/angular,kevmoo/angular,angulardart/angular,chalin/angular2,chalin/angular2,kevmoo/angular,matanlurey/angular,matanlurey/angular,angulardart/angular