[PROJ] Geoidmodel in WKT without grid file

[Even Rouault]

Javier,

The code paths that deal with the GEOIDMODEL[] and finding a transformation 
from/into a VerticalCRS aren't exactly the same. In the code path of the 
GEOIDMODEL[], no ballpark vertical transformation was added, so when the grid 
is missing, no transformation can be done.

I've addressed this per https://github.com/OSGeo/PROJ/pull/2449 by making sure 
a ballpart vertical transformation is also added

Even

-- 
Spatialys - Geospatial professional services
http://www.spatialys.com