Change log level of CertificateError within match_hostname (urllib3#1657)

Author: sethmlarson

src/urllib3/connection.py

@@ -429,7 +429,7 @@ def _match_hostname(cert, asserted_hostname):
     try:
         match_hostname(cert, asserted_hostname)
     except CertificateError as e:
-        log.error(
+        log.warning(
             "Certificate did not match expected hostname: %s. " "Certificate: %s",
             asserted_hostname,
             cert,

test/test_connection.py

@@ -32,7 +32,7 @@ def test_match_hostname_mismatch(self):
         cert = {"subjectAltName": [("DNS", "foo")]}
         asserted_hostname = "bar"
         try:
-            with mock.patch("urllib3.connection.log.error") as mock_log:
+            with mock.patch("urllib3.connection.log.warning") as mock_log:
                 _match_hostname(cert, asserted_hostname)
         except CertificateError as e:
             assert "hostname 'bar' doesn't match 'foo'" in str(e)