Restore UEFI configuration to IMM systems

The work to migrate newer systems to redfish unfortunately
broke ability to work with older IMM based systems.

Use the lack of redfish in the class to indicate that the system
predates this and should use IPMI.

Change-Id: I8ca2782e81984a86ddb5f2ded358bbfad07be46d

pyghmi/ipmi/oem/lenovo/config.py

@@ -272,7 +272,9 @@ class LenovoFirmwareConfig(object):
             cfgfilename = "config"
         options = {}
         data = None
-        if self.connection:
+        if not hasattr(self.xc, 'grab_redfish_response_with_status'):
+            rsp = ({}, 500)
+        elif self.connection:
             rsp = ({}, 200)
         else:
             rsp = self.xc.grab_redfish_response_with_status(