GeoJson: pages show json instead of map as of MW 1.39

[krabina]

Issue

Since MW 1.39, pages in the GeoJson namespace show their json structure:
https://maps.extension.wiki/wiki/GeoJson:Berlin
Before that they showed the map with the GeoJson editor, which is of course the preferred solution in case of geojson data.

Is there any way to bring back the old behavior also in 1.39?