test_imaplib: skip check_hostname test when SNI is not available

Lib/test/test_imaplib.py

@@ -18,6 +18,9 @@ try:
     import ssl
 except ImportError:
     ssl = None
+    HAS_SNI = False
+else:
+    from ssl import HAS_SNI
 
 CERTFILE = None
 CAFILE = None
@@ -349,6 +352,7 @@ class ThreadedNetworkedTestsSSL(BaseThreadedNetworkedTests):
     imap_class = IMAP4_SSL
 
     @reap_threads
+    @unittest.skipUnless(HAS_SNI, 'No SNI support in ssl module')
     def test_ssl_verified(self):
         ssl_context = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
         ssl_context.verify_mode = ssl.CERT_REQUIRED