Add router create miss one option

"openstack router create" command miss [--ha {True,False}] option.

For more detail:

+ When running "neutron router-create --help" command, we have the result like below:

usage: neutron router-create [-h] [-f {json,shell,table,value,yaml}]
                             [-c COLUMN] [--max-width <integer>] [--noindent]
                             [--prefix PREFIX] [--request-format {json}]
                             [--tenant-id TENANT_ID] [--admin-state-down]
                             [--description DESCRIPTION]
                             [--distributed {True,False}] [--ha {True,False}]
                             [--availability-zone-hint AVAILABILITY_ZONE]
                             NAME

+ When running "openstack router create --help" command, we have:

usage: openstack router create [-h] [-f {json,shell,table,value,yaml}]
                               [-c COLUMN] [--max-width <integer>]
                               [--noindent] [--prefix PREFIX]
                               [--enable | --disable] [--distributed]
                               [--project <project>]
                               [--project-domain <project-domain>]
                               [--availability-zone-hint <availability-zone>]
                               <name>

==> For "openstack router create --help" command, it miss [--ha {True,False}] option.