Remove invalid link (#3132) (#3142)

free-programming-books.md

@@ -2106,7 +2106,6 @@ Kerridge (PDF) (email address *requested*, not required)
 * [Google's Python Style Guide](https://google.github.io/styleguide/pyguide.html)
 * [Hacking Secret Cyphers with Python](http://inventwithpython.com/hacking/chapters/) - Al Sweigart (3.3)
 * [Hadoop with Python](http://www.oreilly.com/programming/free/hadoop-with-python.csp) (email address *requested*, not required)
-* [High Performance Python](http://ianozsvald.com/HighPerformancePythonfromTrainingatEuroPython2011_v0.2.pdf) (PDF)
 * [Hitchhiker's Guide to Python!](http://docs.python-guide.org/en/latest/) (2.6)
 * [How to Make Mistakes in Python](http://www.oreilly.com/programming/free/files/how-to-make-mistakes-in-python.pdf) - Mike Pirnat (PDF) (1st edition)
 * [How to Think Like a Computer Scientist: Learning with Python, Interactive Edition](http://interactivepython.org/courselib/static/thinkcspy/index.html) (3.2)