Only use default map type if config is wrong
Only use default map type if config is wrong

With 4ee9f02 the map type defaulted to `ROADMAP` if it was not one of the
accepted ones. But the condition is only half inverted and thus will always
default to `ROADMAP` instead just when an incorrect was used.

espinosaluis/TrackMeViewer,espinosaluis/TrackMeViewer