Add guard code for if Mapillary viewer could not be initialized
Add guard code for if Mapillary viewer could not be initialized

digidem/iD,ngageoint/hootenanny-ui,AndreasHae/iD,ngageoint/hootenanny-ui,kartta-labs/iD,morray/iD,digidem/iD,openstreetmap/iD,kartta-labs/iD,openstreetmap/iD,openstreetmap/iD,morray/iD,AndreasHae/iD,kartta-labs/iD,ngageoint/hootenanny-ui,AndreasHae/iD