T5148: Add smoketest for plugin openvpn-otp OpenVPN

[sever-sever]

Change Summary

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• Other (please describe): Add smoketest for plugin openvpn-otp OpenVPN

Related Task(s)

• https://vyos.dev/T5148

Component(s) name

openvpn

Proposed changes

How to test

vyos@r14:~$ /usr/libexec/vyos/tests/smoke/cli/test_interfaces_openvpn.py
test_openvpn_client_interfaces (__main__.TestInterfacesOpenVPN.test_openvpn_client_interfaces) ... ok
test_openvpn_client_verify (__main__.TestInterfacesOpenVPN.test_openvpn_client_verify) ... ok
test_openvpn_options (__main__.TestInterfacesOpenVPN.test_openvpn_options) ... ok
test_openvpn_server_net30_topology (__main__.TestInterfacesOpenVPN.test_openvpn_server_net30_topology) ... ok
test_openvpn_server_subnet_topology (__main__.TestInterfacesOpenVPN.test_openvpn_server_subnet_topology) ... ok
test_openvpn_server_verify (__main__.TestInterfacesOpenVPN.test_openvpn_server_verify) ... ok
test_openvpn_site2site_interfaces_tun (__main__.TestInterfacesOpenVPN.test_openvpn_site2site_interfaces_tun) ... ok
test_openvpn_site2site_verify (__main__.TestInterfacesOpenVPN.test_openvpn_site2site_verify) ... ok

----------------------------------------------------------------------
Ran 8 tests in 104.421s

OK
vyos@r14:~$ 

Checklist:

• I have read the CONTRIBUTING document
• I have linked this PR to one or more Phabricator Task(s)
• I have run the components SMOKETESTS if applicable
• My commit headlines contain a valid Task id
• My change requires a change to the documentation
• I have updated the documentation accordingly