Add username-as-common-name if the certificate authentication is not enabled.

templates/server.conf.j2

@@ -40,9 +40,7 @@ compress lz4-v2
 push "compress lz4-v2"
 {% endif %}
 keepalive {{ openvpn_keepalive }}
-{% if openvpn_cert_auth_enabled %}
 tls-server
-{% endif %}
 tls-auth {{ openvpn_tls_auth }} 0
 key-direction 0
 dh {{ openvpn_dh }}
@@ -52,6 +50,7 @@ key {{ openvpn_key }}
 {% if not openvpn_cert_auth_enabled %}
 # Disable cert-auth
 client-cert-not-required
+username-as-common-name
 {% endif %}
 {% if openvpn_username_pam_auth %}
 username-as-common-name