Fix test: don't register the same user twice
Fix test: don't register the same user twice

inteligencia-coletiva-lsd/pybossa,Scifabric/pybossa,inteligencia-coletiva-lsd/pybossa,stefanhahmann/pybossa,jean/pybossa,stefanhahmann/pybossa,geotagx/pybossa,OpenNewsLabs/pybossa,PyBossa/pybossa,Scifabric/pybossa,OpenNewsLabs/pybossa,geotagx/pybossa,jean/pybossa,PyBossa/pybossa