Replaced dead "HPC is dying, and MPI is killing it" hyperlink For Lec 30

[Alluq]

Lecture 30's article on MPI is dead so I replaced it with the correct one for convenience.

Turns out they changed their routes

http://www.dursi.ca/hpc-is-dying-and-mpi-is-killing-it/

is now

http://www.dursi.ca/post/hpc-is-dying-and-mpi-is-killing-it/