Change any23.microdata.ns.default configuration value to http://schema.org

./api/src/main/resources/default-configuration.properties uses the very old (deprecated) http://rdf.data-vocabulary.org namespace as a default namespace for prepending to Microdata extractions.

# ---- Microdata default namespace.
any23.microdata.ns.default=http://rdf.data-vocabulary.org/

For obvious reasons we should change this to http://schema.org