setup.py: update URL to pagure.io

The canonical version of this code now lives in Pagure. Replace the
reference to Jay's version.

Signed-off-by: Ken Dreyer <kdreyer@redhat.com>

setup.py

@@ -21,7 +21,7 @@ setup(
     author_email = "jgregusk@redhat.com",
     description = ("module for determining if a package is multilib"),
     license = "GPLv2",
-    url = "https://github.com/Zyzyx/python-multilib.git",
+    url = "https://pagure.io/releng/python-multilib",
     packages = packages,
     install_requires = ['six'],
     package_data = {'': ['README.md', 'LICENSE']},