DOC: Fixed name of .so file in userguide's numpy_tutorial.
DOC: Fixed name of .so file in userguide's numpy_tutorial.

"convolve_cy.so" -> "compute_cy.so" to match imports used in this tutorial.

scoder/cython,cython/cython,scoder/cython,scoder/cython,da-woods/cython,cython/cython,da-woods/cython,da-woods/cython,scoder/cython,cython/cython,da-woods/cython,cython/cython