Fix misspellings in python openstackclient

Fix misspellings detected by:
* pip install misspellings
* git ls-files | grep -v locale | misspellings -f -

Change-Id: Ic0d3efa26eb9a05ce16a8319c142f5bd1ce23821
Closes-Bug: #1257295
Merge "Fix misspellings in python openstackclient"