src/sage/graphs/graph.py: Remove outdated reference to jmol in docstring

Author: Matthias Koeppe

src/sage/graphs/graph.py

@@ -362,7 +362,7 @@
     sage: G = graphs.RandomGNP(15,.3)
     sage: G.show()                                                                      # needs sage.plot
 
-And you can view it in three dimensions via jmol with ``show3d()``. ::
+And you can view it in three dimensions with ``show3d()``. ::
 
     sage: G.show3d()                                                                    # needs sage.plot