grooveshark: fix test if user is not logged
grooveshark: fix test if user is not logged

Signed-off-by: Pierre Mazière <de7336e35cef0f8a399cd781635c22e507b4a7ab@gmx.com>

RouxRC/weboob,willprice/weboob,yannrouillard/weboob,yannrouillard/weboob,frankrousseau/weboob,frankrousseau/weboob,frankrousseau/weboob,nojhan/weboob-devel,willprice/weboob,Konubinix/weboob,nojhan/weboob-devel,RouxRC/weboob,Konubinix/weboob,sputnick-dev/weboob,Boussadia/weboob,Boussadia/weboob,Boussadia/weboob,laurent-george/weboob,Konubinix/weboob,Boussadia/weboob,laurent-george/weboob,nojhan/weboob-devel,laurent-george/weboob,RouxRC/weboob,sputnick-dev/weboob,willprice/weboob,sputnick-dev/weboob,yannrouillard/weboob