maps: Statkart update to v4

src/QtLocationPlugin/QGCMapUrlEngine.cpp

@@ -269,7 +269,7 @@ UrlFactory::_getURL(MapType type, int x, int y, int zoom, QNetworkAccessManager*
 #endif
     case StatkartTopo:
     {
-        return QString("http://opencache.statkart.no/gatekeeper/gk/gk.open_gmaps?layers=topo2&zoom=%1&x=%2&y=%3").arg(zoom).arg(x).arg(y);
+        return QString("http://opencache.statkart.no/gatekeeper/gk/gk.open_gmaps?layers=topo4&zoom=%1&x=%2&y=%3").arg(zoom).arg(x).arg(y);
     }
     break;
     case EniroTopo: