Ciao vmicho

I passed by https://www.openstreetmap.org/way/1155425895/ by chance.

Mapping a communal grave [1] with `barrier=retaining_wall` and `leisure=garden` seems wrong, and - in my opinion - tagging for the renderer.

According to https://wiki.openstreetmap.org/wiki/Friedhofmapping (unfortunately only in German), I've updated it to `historic=tomb` and `tomb=columbarium`.

Happy mapping,
habi 

[1]: Here's a link to a photo of mine, valid for some days: https://share.icloud.com/photos/07bWjQU6yQNZXmYl4Kuj9oigg