Update integer field to null/undefined value

[dbauszus-glx]

The location update fails trying to remove the integer value.

{
  "title": "minutes",
  "field": "minutes",
  "filter": {
    "type": "integer"
   },
  "edit": true
}

A null value should be possible on the integer field.

The schema for the test table is pretty straightforward.

create table scratch_4326 (
  id SERIAL,
  location varchar,
  geom geometry,
  minutes integer
);

CREATE INDEX public_scratch_4326_geom
  ON public.scratch_4326
  USING GIST (geom);