Ensure suppressing urllib3 warning works correctly

On some platforms (RHEL7 using ansible) the warnings are not being suppressed.
Looking into this, the try-except block failed with the error `cannot import name InsecurePlatformWarning`.
So it is safer to import and filter each warning individually.

This fixes ansible/ansible#20006

winrm/transport.py

@@ -1,8 +1,10 @@
 from __future__ import unicode_literals
 from contextlib import contextmanager
+import errno
 import re
 import sys
 import os
+import time
 import weakref
 
 is_py2 = sys.version[0] == '2'
@@ -189,7 +191,18 @@ def send_message(self, message):
         prepared_request = self.session.prepare_request(request)
 
         try:
-            response = self.session.send(prepared_request, timeout=self.read_timeout_sec)
+
+            for retry in range(5):
+                try:
+                    response = self.session.send(prepared_request, timeout=self.read_timeout_sec)
+                    break
+                except requests.exceptions.ConnectionError as e:
+                    if e.args[0].reason.errno != errno.ECONNREFUSED:
+                        raise
+                    if retry == 4:
+                        raise
+                    time.sleep(5)
+
             response_text = response.text
             response.raise_for_status()
             return response_text