Move ironic client attribute to correct class

The _ironic_client attribute is useful only for the OperatorCloud
class, so having it defined in OpenStackCloud is bad programming
style. Move it to where it is used.

Change-Id: I8141e1758e28a8120f0e78c9e407bb416a499166

shade/openstackcloud.py

@@ -216,7 +216,6 @@ class OpenStackCloud(object):
         self._glance_client = None
         self._glance_endpoint = None
         self._heat_client = None
-        self._ironic_client = None
         self._keystone_client = None
         self._neutron_client = None
         self._nova_client = None

shade/operatorcloud.py

@@ -32,6 +32,10 @@ class OperatorCloud(openstackcloud.OpenStackCloud):
     See the :class:`OpenStackCloud` class for a description of most options.
     """
 
+    def __init__(self, *args, **kwargs):
+        super(OperatorCloud, self).__init__(*args, **kwargs)
+        self._ironic_client = None
+
     # Set the ironic API microversion to a known-good
     # supported/tested with the contents of shade.
     #