Modify "nova keypair-show" Positional arguments help information
Modify "nova keypair-show" Positional arguments help information

CLI "nova keypair-show <keypair>", Positional arguments:
  <keypair> Name or ID of keypair
But in fact, it does not support ID,when using ID, the error is as follows:
[root]# nova keypair-show 631
ERROR (CommandError): No keypair with a name or ID of '631' exists.
So it is needed to change the Positional arguments help information
from "Name or ID of keypair" to "Name of keypair".

Change-Id: I4cd022a6aa1ca937e7aeb33847dc3ce2d6d5690e
Closes-Bug: #1493212
Signed-off-by: Xiaowei Qian <80525a16cc43a9736ee9ebdb6c2bc4e30017f5a1@cn.fujitsu.com>

mat128/python-novaclient,mat128/python-novaclient