fixed #8003 dropdown throws "event is not defined" error in PrimeNG v8.0.2 on Firefox
fixed #8003 dropdown throws "event is not defined" error in PrimeNG v8.0.2 on Firefox

primefaces/primeng,primefaces/primeng,WebRota/primeng,WebRota/primeng,primefaces/primeng,WebRota/primeng,WebRota/primeng,primefaces/primeng