Support for contact:website in OSM data

[lliehu]

Right now, the map doesn't display contact website for Niihaman Ulkoilumaja. The reason seems to be that it's tagged as contact:website instead of website in OSM data. According to OpenStreetMap Wiki and taginfo statistics shown there, both keys are commonly used for the same purpose. Thus it would be good if contact:website was also supported. By the way, this same contact namespace exists also for other contact details like email.

References:
https://wiki.openstreetmap.org/wiki/Key:website
https://wiki.openstreetmap.org/wiki/Key:contact:website