remove unneeded check which introduces a bug
remove unneeded check which introduces a bug

There is a verify_type call a few lines lower which does exactly what we
need without causing strange errors when you are using type members with
underscores.

AKHarris/jsonapi-resources,localytics/jsonapi-resources,senid231/jsonapi-resources,Skeduna/jsonapi-resources,kevintraver/jsonapi-resources,togglepro/jsonapi-resources,harisadam/jsonapi-resources,cerebris/jsonapi-resources,jsmestad/jsonapi-resources