Homepage: Fixed typo pypy -> pypi. Thanks to sebest

docs/homepage/index.html

@@ -89,7 +89,7 @@ pageTracker._trackPageview();
         Celery is easy to integrate with Django, Pylons and Flask, using
         the <a href="http://pypi.python.org/pypi/django-celery">django-celery</a>,
         <a href="http://pypi.python.org/pypi/celery-pylons">celery-pylons</a>
-        and <a href="http://pypy.python.org/pypi/Flask-Celery">Flask-Celery</a>add-on packages.
+        and <a href="http://pypi.python.org/pypi/Flask-Celery">Flask-Celery</a>add-on packages.
 
         <h3>Example</h3>
         <p>This is a simple task adding two numbers:</p>