Updated PEP link to point to the now-canonical site.

Doc/whatsnew/whatsnew20.tex

@@ -138,7 +138,7 @@ Read the rest of PEP 1 for the details of the PEP editorial process,
 style, and format.  PEPs are kept in the Python CVS tree on
 SourceForge, though they're not part of the Python 2.0 distribution,
 and are also available in HTML form from
-\url{http://python.sourceforge.net/peps/}.  As of September 2000,
+\url{http://www.python.org/peps/}.  As of September 2000,
 there are 25 PEPS, ranging from PEP 201, ``Lockstep Iteration'', to
 PEP 225, ``Elementwise/Objectwise Operators''.