When server and management are at different ports, and when server
requires TLS client authentication, then there is no simple method to
disable TLS client authentication for management port.

This commit adds an additional "none" option to ssl.client-auth.

Example:

    server.port=8080
    server.ssl.enabled=true
    server.ssl.client-auth=need
    management.server.port=8081
    management.server.ssl.enabled=true
    management.server.ssl.client-auth=none

See gh-14985