Update URL for "Welcome to Java for Python Programmers" (#3374)

free-programming-books.md

@@ -1464,7 +1464,7 @@ Kerridge (PDF) (email address *requested*, not required)
 * [The Java EE7 Tutorial](https://docs.oracle.com/javaee/7/JEETT.pdf) - Eric Jendrock, et al (PDF)
 * [The Java Tutorials](https://docs.oracle.com/javase/tutorial/index.html)
 * [Think Java: How to Think Like a Computer Scientist](http://greenteapress.com/thinkapjava/) - Allen B. Downey and Chris Mayfield
-* [Welcome to Java for Python Programmers](https://interactivepython.org/runestone/static/java4python/index.html) - Brad Miller
+* [Welcome to Java for Python Programmers](https://runestone.academy/runestone/books/published/java4python/index.html) - Brad Miller
 * [Welcome to the Java Workshop (2006)](http://javaworkshop.sourceforge.net) - Trevor Miller