Skip overzealous test for existence of the online license.html for pre-release versions.

Lib/test/test_site.py

@@ -416,6 +416,8 @@ def test_sitecustomize_executed(self):
                 self.fail("sitecustomize not imported automatically")
 
     @test.support.requires_resource('network')
+    @unittest.skipUnless(sys.version_info[3] == 'final',
+                         'only for released versions')
     def test_license_exists_at_url(self):
         # This test is a bit fragile since it depends on the format of the
         # string displayed by license in the absence of a LICENSE file.