handle empty responses
handle empty responses

kalxas/pycsw,PublicaMundi/pycsw,ingenieroariel/pycsw,mwengren/pycsw,mwengren/pycsw,bukun/pycsw,tomkralidis/pycsw,tomkralidis/pycsw,ocefpaf/pycsw,ricardogsilva/pycsw,benhowell/pycsw,ricardogsilva/pycsw,geopython/pycsw,kevinpdavies/pycsw,PublicaMundi/pycsw,geopython/pycsw,benhowell/pycsw,ckan-fcd/pycsw-fcd,ocefpaf/pycsw,bukun/pycsw,kalxas/pycsw,bukun/pycsw,tomkralidis/pycsw,geopython/pycsw,kalxas/pycsw,kevinpdavies/pycsw,ricardogsilva/pycsw,rouault/pycsw,ckan-fcd/pycsw-fcd,rouault/pycsw,ingenieroariel/pycsw