Remove stale setting of health attribute.

A contributor made a change, but neglected to remove the stale line they
were replacing.

Change-Id: Id8c4cecc64792681192f749890eb53a063ff6f15

pyghmi/redfish/command.py

@@ -123,7 +123,6 @@ class SensorReading(object):
                 'Status', {}).get('Health', None), const.Health.Warning)
             self.states = [healthinfo.get('Status', {}).get('Health',
                                                             'Unknown')]
-            self.health = _healthmap[healthinfo['Status']['Health']]
             if self.health == const.Health.Ok:
                 self.states = []
         self.value = value