[fix] Fix zc.recipe.egg tests with recent setuptools

With recent setuptools, the way the test package index is laid out
causes a warning log to be emitted, which needs to be filtered out
to keep matching the expected test output.

zc.recipe.egg_/src/zc/recipe/egg/tests.py

@@ -101,6 +101,12 @@ def test_suite():
                zc.buildout.testing.normalize_endings,
                zc.buildout.testing.not_found,
                zc.buildout.testing.root_logger_messages,
+               # Setuptools may emit this warning if it hasn't yet indexed
+               # the index page of the test package index (at <index-url>)
+               # because it starts by looking at <index-url>/<package-name>
+               # and warns if it needs to fallback to scanning <index-url>.
+               (re.compile(r"Couldn't find index page for 'demo' .*\r?\n"),
+                ''),
                ])
             ),
         doctest.DocFileSuite(