using system level urllib3 if not preent in requests package

Some requests packages have their own urllib3 package bundled but some others
don't. Need to take care of both the cases
Closes-Bug: #1689675
Closes-Bug: #1691603
Change-Id: Ia88e5e110544e8f4c2a3ac2dc5b72ed0fa0d087b
(cherry picked from commit b866f79)

src/config/utils/contrail-status.py

@@ -11,12 +11,19 @@
 import ConfigParser
 import socket
 import requests
-from requests.packages.urllib3.exceptions import SubjectAltNameWarning
+try:
+    from requests.packages.urllib3.exceptions import SubjectAltNameWarning
+    warnings.filterwarnings('ignore', category=SubjectAltNameWarning)
+except:
+    try:
+        from urllib3.exceptions import SubjectAltNameWarning
+        warnings.filterwarnings('ignore', category=SubjectAltNameWarning)
+    except:
+        pass
 import warnings
 warnings.filterwarnings('ignore', ".*SNIMissingWarning.*")
 warnings.filterwarnings('ignore', ".*InsecurePlatformWarning.*")
 warnings.filterwarnings('ignore', ".*SubjectAltNameWarning.*")
-warnings.filterwarnings('ignore', category=SubjectAltNameWarning)
 from StringIO import StringIO
 from lxml import etree
 from sandesh_common.vns.constants import ServiceHttpPortMap, \