remove redundant line and replace octavia user

remove redundant space line
replace octavia user with {{ octavia_keystone_user }}

Change-Id: I284acc580a1a530eede3e0227febe8667dea5d47

ansible/roles/octavia/templates/octavia-openrc.sh.j2

@@ -3,9 +3,8 @@ for key in $( set | awk '{FS="="}  /^OS_/ {print $1}' ); do unset $key ; done
 export OS_PROJECT_DOMAIN_NAME=Default
 export OS_USER_DOMAIN_NAME=Default
 export OS_PROJECT_NAME={{ octavia_service_auth_project }}
-export OS_USERNAME=octavia
+export OS_USERNAME={{ octavia_keystone_user }}
 export OS_PASSWORD={{ octavia_keystone_password }}
 export OS_AUTH_URL={{ keystone_admin_url }}/v3
 export OS_INTERFACE=internal
 export OS_ENDPOINT_TYPE=internalURL
-