bpo-25404: SSLContext.load_dh_params() non-ASCII path (GH-3459)

SSLContext.load_dh_params() now supports non-ASCII path.

Signed-off-by: Christian Heimes <christian@python.org>
diff --git a/Lib/test/test_ssl.py b/Lib/test/test_ssl.py
index f172520..b59fe73 100644
--- a/Lib/test/test_ssl.py
+++ b/Lib/test/test_ssl.py
@@ -14,7 +14,7 @@
 import os
 import errno
 import pprint
-import tempfile
+import shutil
 import urllib2
 import traceback
 import weakref
@@ -1000,6 +1000,10 @@
         self.assertEqual(cm.exception.errno, errno.ENOENT)
         with self.assertRaises(ssl.SSLError) as cm:
             ctx.load_dh_params(CERTFILE)
+        with support.temp_dir() as d:
+            fname = os.path.join(d, u'dhpäräm.pem')
+            shutil.copy(DHFILE, fname)
+            ctx.load_dh_params(fname)
 
     @skip_if_broken_ubuntu_ssl
     def test_session_stats(self):