Issue #7449, last part (11): fix many tests if thread support is disabled
* Use try/except ImportError or test_support.import_module() to import thread
and threading modules
* Add @unittest.skipUnless(threading, ...) to testcases using threads
diff --git a/Lib/test/test_ftplib.py b/Lib/test/test_ftplib.py
index 4f6d1c1..3a2ec5e 100644
--- a/Lib/test/test_ftplib.py
+++ b/Lib/test/test_ftplib.py
@@ -4,7 +4,6 @@
# environment
import ftplib
-import threading
import asyncore
import asynchat
import socket
@@ -19,6 +18,7 @@
from unittest import TestCase
from test import test_support
from test.test_support import HOST
+threading = test_support.import_module('threading')
# the dummy data returned by server over the data channel when