Remove mod_wsgi test client's dependency on py3compat.

test/mod_wsgi_test/test_client.py

@@ -21,12 +21,18 @@ import time
 
 from optparse import OptionParser
 
-from bson.py3compat import PY3, thread
-
-if PY3:
-    from urllib.request import urlopen
-else:
+try:
     from urllib2 import urlopen
+except ImportError:
+    # Python 3.
+    from urllib.request import urlopen
+
+
+try:
+    import thread
+except ImportError:
+    # Python 3.
+    import _thread as thread
 
 
 def parse_args():