reproxy doesn't update allowed FQDNs for SSL after it's startup

[Semior001]

On startup, if FQDNs are not defined in the environment variables, reproxy loads the FQDNs from the discovered servers (see: https://github.com/umputun/reproxy/blob/master/app/proxy/proxy.go#L150-L153).

However, when the list of containers is updated or the configuration file is modified, reproxy does not automatically update its list of FQDNs. As a result, a restart of reproxy is required to reflect these changes.