rdfparser.js: fix elementURI scope (this=RDFParser)
rdfparser.js: fix elementURI scope (this=RDFParser)

ariutta/rdflib.js,ariutta/rdflib.js,redaktor/rdflib.js,timbl/rdflib.js,nicola/rdflib.js,redaktor/rdflib.js,timbl/rdflib.js,timbl/rdflib.js,nicola/rdflib.js,ariutta/rdflib.js