trivial fix to graph.query from comments on http://code.google.com/p/rdflib/wiki/IntroSparql
trivial fix to graph.query from comments on http://code.google.com/p/rdflib/wiki/IntroSparql

git-svn-id: 60eb48102d1ca0c284ab3654bef916b01e1b221b@1893 4f84a9ca-5c3e-0410-8a68-0bdf370325d5

nwebs/rdflib