Broken compatibility with py2.7

Hi,
I'm trying to use ckanext-spatial (with harvester for csw iso19139),

I'm over a fresh (docker) installation of ckan-2.8 and python 2.7 and I've just realized that 5 months ago a massive change (https://github.com/ckan/ckanext-spatial/pull/249) has been merged (impressive job!).

Even if that is really appreciated for the py3 migration, it looks like it is not working anymore on python2.7.

I've fixed it (the portion I'm testing) and I'm wondering if a pull req will be acceptable on master to keep it working with python2 AND python3, the patch is not invasive but adds some static logic to check the encoding.

What do you think?

Feedback is welcome