Changed `pop` to `get` in ArrayField so models can be loaded multiple times.
Changed `pop` to `get` in ArrayField so models can be loaded multiple times.

As is, on second load (possibly from Django migrations) models using ArrayField
with `dbtype` would lose that `dbtype` when creating migrations.  Closes issue #46.

Natgeoed/djorm-ext-pgarray,natgeo/djorm-ext-pgarray,niwinz/djorm-pgarray,Natgeoed/djorm-ext-pgarray,niwinz/djorm-pgarray,natgeo/djorm-ext-pgarray