test: Do not hardcode listening port in testHttpNetlocIPv6.

caucase/test.py

@@ -2565,8 +2565,12 @@ class CaucaseTest(unittest.TestCase):
     self._stopServer()
     os.unlink(self._server_key)
     os.unlink(self._server_db)
-    self._server_netloc = '[::1]:8000'
-    self._caucase_url = 'http://' + self._server_netloc
+    netloc = '[::1]'
+    port = urlparse.urlparse(self._caucase_url).port
+    if port:
+        netloc += ':%s' % port
+    self._server_netloc = netloc
+    self._caucase_url = 'http://' + netloc
     self._startServer()
     user_key_path = self._createFirstUser()
     service_key = self._createAndApproveCertificate(
@@ -2584,7 +2588,7 @@ class CaucaseTest(unittest.TestCase):
       x509.CRLDistributionPoints,
     ).value
     uri, = distribution_point.full_name
-    self.assertEqual(uri.value, u'http://[::1]:8000/cas/crl')
+    self.assertEqual(uri.value, self._caucase_url + u'/cas/crl')
 
   def testServerFilePermissions(self):
     """