Increase max_zoom from 14 to 15 in MTBmapno.geojson - #2845

INFO:root:Processing sources/europe/no/MTBmapno.geojson
INFO:root:Type: tms
INFO:root:Zoom levels reachable. (Tested: 3,4,5,6,7,8,9,10,11,12,13,14,15)
ERROR:root:sources/europe/no/MTBmapno.geojson has no license_url set
ERROR:root:sources/europe/no/MTBmapno.geojson has no privacy_policy_url. Adding privacy policies to sources is important to comply with legal requirements in certain countries.

The PR check is stricter now, if there is no privacy policy, you can set privacy_policy_url: false.

I'm not across the licensing/permissions for this source, but there's no license_url set.

The Website say "© OpenStreetMap | © Kartverket | © mtbmap.no" so there's more copyright than just OSM. I can see hillshading and contours, where are these sourced and are these okay for tracing from?

I know you're just changing the maxzoom, but it's also a good time to ensure we can use this source for mapping.