Fix typo in 02.07-Fancy-Indexing
Fix typo in 02.07-Fancy-Indexing

The second reference to `x[3]` in "You might expect that x[3] would contain the value 2, and x[3] would contain the value 3," should be x[4].
jakevdp/PythonDataScienceHandbook,jakevdp/PythonDataScienceHandbook