Steeltoe vulnerable to management-port isolation bypass via spoofed Host header

Steeltoe is an open source project that provides a collection of libraries that helps users build cloud-native applications. When Steeltoe management endpoints versions 3.2.2 through 3.3.0 and 4.1.0 are configured to listen on an alternate port (`Management:Endpoints:Port` is configured), the middleware responsible for restricting access to the endpoints uses the `Host` HTTP header rather than the actual network socket port. Versions 3.4.0 and 4.2.0 patch the issue. If an immediate upgrade to a patched version is not possible, add explicit ASP.NET Core authorization (`RequireAuthorization`) to all sensitive actuator endpoints as a defense-in-depth measure independent of port isolation and/or configure the reverse proxy or load balancer to enforce the `Host` header value and prevent clients from setting an arbitrary port.