Function jsonrpc_server_utils::cors::get_cors_allow_origin

pub fn get_cors_allow_origin(
    origin: Option<&str>, 
    host: Option<&str>, 
    allowed: &Option<Vec<AccessControlAllowOrigin>>
) -> AllowCors<AccessControlAllowOrigin>

Returns correct CORS header (if any) given list of allowed origins and current origin.