Don't log traceback for redis ConnectionError exception

In partition_handler, the redis connection timesout if there is no
activity for 90 seconds. We have catch all exception that logs the
traceback. Need to catch the ConnectionError exception and not log the
traceback for this case.

Change-Id: If2f391d5ddf3a04aed82b889b1d780de60c4da6b
Closes-Bug: #1578779

src/opserver/partition_handler.py

@@ -417,13 +417,16 @@ def _run(self):
 
             except gevent.GreenletExit:
                 break
+            except redis.exceptions.ConnectionError:
+                pass
             except Exception as ex:
                 template = "Exception {0} in uve stream proc. Arguments:\n{1!r}"
                 messag = template.format(type(ex).__name__, ex.args)
                 self._logger.error("[%s:%d] AlarmGen %s,%d %s : traceback %s" % \
                                   (self._pi.ip_address, self._pi.port, \
                                    self._pi.instance_id, self._partno, \
                                    messag, traceback.format_exc()))
+            finally:
                 lredis = None
                 if pb is not None:
                     pb.close()