error_code of BotoServerError is wrong

Line 361 of client.py judges the error_code of exception BotoServerError, which is as follows:

 360 except boto.exception.BotoServerError, e:
 361 if e.status == 400 and e.error_code == 'UserNotFound':
 362 return None
 363 raise

While the error_code is not used in boto-1.9b, and the corresponding error_code is 'NotFound', so line of 361 should be:

 361 if e.status == 400 and e.error_code == 'NotFound':

Please check it.