Test DB Creation doesn't create PointField with db_index=True

[Christoph Heer]

I want to test my GeoDjango project but by creation of the test database I got following error:

Creating test database for alias 'default'...
Failed to install index for map.OSMPlace model: column "point" does not exist

It is correct the Table map_osmplace exists without a point column.

from django.contrib.gis.db import models
point = models.PointField(db_index=True)

Another table without an index on the point field contains the point column.

[Claude Paroz]

Same issue as #20758