Handle firmware upload error 413

If software attempts to upload a file
larger than the XCC supports.  Report
a more understandable condition in
such a case.

Change-Id: I8b5a80c0be8fbca141bdce34d5da39095217b30b

pyghmi/ipmi/oem/lenovo/imm.py

@@ -1455,6 +1455,8 @@ class XCCClient(IMMClient):
                 progress({'phase': 'upload',
                           'progress': 100.0 * rsp['received'] / rsp['size']})
             elif rsp['state'] != 'done':
+                if rsp.get('status', None) == 413:
+                    raise Exception('File is larger than supported')
                 raise Exception('Unexpected result:' + repr(rsp))
             uploadstate = rsp['state']
             self._refresh_token()