Describe the bug
I don't know if it is a bug or a feature but middlewares seems to influence other http applications.

It is an issue in my case since I have a fallback function to send a custom 404 mesage.

To Reproduce
If we take the following code:

val app1 = ???
val app2 = ???
val app3 = ???

val app = app1 ++ app2 @@ bearerAuth(token => true) ++ app3

The app3 will also have the bearer middleware but not the app1.

Expected behaviour
app3 doesn't need token.