Use ID instead of Name in secgroup_delete_rule
Use ID instead of Name in secgroup_delete_rule

In trove secgroup_delete_rule help message, the parameters
<security_group_rule> is described "Name of security group rule".
In fact, security group rule has not attribute 'name', it only has
'id'.
Users could use trove secgroup-list-rules to get all ID of rules.

Change-Id: If5b97f744b24838e6aa61f4c96608da569886dd2

openstack/python-troveclient,openstack/python-troveclient