Fix test_httplib when built without threads
diff --git a/Lib/test/ssl_servers.py b/Lib/test/ssl_servers.py
index 14d6aeb..da27c3a 100644
--- a/Lib/test/ssl_servers.py
+++ b/Lib/test/ssl_servers.py
@@ -3,13 +3,13 @@
import ssl
import pprint
import socket
-import threading
import urllib.parse
# Rename HTTPServer to _HTTPServer so as to avoid confusion with HTTPSServer.
from http.server import (HTTPServer as _HTTPServer,
SimpleHTTPRequestHandler, BaseHTTPRequestHandler)
from test import support
+threading = support.import_module("threading")
here = os.path.dirname(__file__)