background.js: correctly encode URI components
background.js: correctly encode URI components

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