Using a http-listener without the redirect-socket attribute requires the configuration to define a socket-binding with name "https".

The following error is produced attempting to configure wildfly without https:

ERROR [org.jboss.as.controller.management-operation] (Controller Boot Thread) JBAS014613: Operation ("add") failed - address: ([
    ("subsystem" => "undertow"),
    ("server" => "default-server"),
    ("http-listener" => "default")
]) - failure description: {"JBAS014771: Services with missing/unavailable dependencies" => ["jboss.undertow.listener.default is missing [jboss.binding.https]"]}

I believe this constant is defined in ListenerResourceDefinition on line 80.

If this is the desired behavior, the undertow schema should probably be updated to make redirect-socket required or at least document the dependency.