fix for GRAPH ?var bindings when a single graph is the 'active' graph
fix for GRAPH ?var bindings when a single graph is the 'active' graph

marma/rdflib,yingerj/rdflib,RDFLib/rdflib,avorio/rdflib,ssssam/rdflib,marma/rdflib,RDFLib/rdflib,armandobs14/rdflib,armandobs14/rdflib,avorio/rdflib,marma/rdflib,armandobs14/rdflib,ssssam/rdflib,yingerj/rdflib,dbs/rdflib,ssssam/rdflib,dbs/rdflib,yingerj/rdflib,ssssam/rdflib,yingerj/rdflib,armandobs14/rdflib,dbs/rdflib,marma/rdflib,avorio/rdflib,RDFLib/rdflib,dbs/rdflib,RDFLib/rdflib,avorio/rdflib