Fix cluster_id field when listing events
Fix cluster_id field when listing events

The column "cluster_id" should be short by default.

Change-Id: If8f72ab25f2c82d1943c9f2cc538689a6180c6c4
Closes-Bug: #1642825

stackforge/python-senlinclient,openstack/python-senlinclient,openstack/python-senlinclient,stackforge/python-senlinclient