get_coordlist is not covered by tests

[whatnick]

Description

get_coordlist function in data.py is not covered by unit tests.

https://app.codecov.io/gh/opendatacube/datacube-ows/blob/master/datacube_ows%2Fdata.py#L614

Steps to Reproduce

Review coverage results

Context (Environment)

datacube-ows version (datacube-ows-update --version):

ows_config.py file (link, sample code)

datacube product metadata (datacube product show product_name)