Remove raw traceback (#1221)

Author: dbgasaway

kafka/conn.py

@@ -7,7 +7,7 @@
 from random import shuffle, uniform
 import socket
 import time
-import traceback
+import sys
 
 from kafka.vendor import six
 
@@ -614,8 +614,10 @@ def close(self, error=None):
         """
         if self.state is ConnectionStates.DISCONNECTED:
             if error is not None:
-                log.warning('%s: close() called on disconnected connection with error: %s', self, error)
-                traceback.print_stack()
+                if sys.version_info >= (3, 2):
+                    log.warning('%s: close() called on disconnected connection with error: %s', self, error, stack_info=True)
+                else:
+                    log.warning('%s: close() called on disconnected connection with error: %s', self, error)
             return
 
         log.info('%s: Closing connection. %s', self, error or '')