Contact page causes Google Maps deprecation warning

[Piedone]

Opening the /contact page causes the following warnings in the browser console:

google.maps.event.addDomListener() is deprecated, use the standard addEventListener() method instead: https://developer.mozilla.org/docs/Web/API/EventTarget/addEventListener
The feature will continue to work and there is no plan to decommission it.

It'd be better to use the new API instead.