"_tls-any" feature needs to be properly documented Or disabled with custom connector

## Bug Report

### Version

### Platform
Everywhere

### Crates
Tonic

### Description
I was using my own TlsConnector with tonic 0.12.x "tls" feature enabled. But I was getting following HttpsUriWithoutTlsSupport error.

This is our code:
```Endpoint::try_from("https://10.0.1.215:443")
.connect_with_connector(connector)```

When we create endpoint and tls feature is enabled => then a None "tls" is attached to the connector. Here is the code: https://github.com/hyperium/tonic/blob/e4ba8b5c0cd1607a80ccfed7988c6874fa99ff38/tonic/src/transport/channel/endpoint.rs#L82

When we call `connect_with_connector` it wraps our PSK connector in another connector : https://github.com/hyperium/tonic/blob/e4ba8b5c0cd1607a80ccfed7988c6874fa99ff38/tonic/src/transport/channel/endpoint.rs#L477

Here is the method: https://github.com/hyperium/tonic/blob/e4ba8b5c0cd1607a80ccfed7988c6874fa99ff38/tonic/src/transport/channel/endpoint.rs#L408

Newly created wrapper connector has the "tls" field set to None. Because the endpoint had the "tls" field set to None.
On that connector when a call() method is called, Then it basically checks for None tls and returns
`HttpsUriWithoutTlsSupport`
So this issue happened because on enabling the "tls" flag. The tonic was wrapping our PSKConnector with its own connector which had Empty/None tls config. And it was throwing error from this location: https://github.com/hyperium/tonic/blob/e4ba8b5c0cd1607a80ccfed7988c6874fa99ff38/tonic/src/transport/channel/service/connector.rs#L68

I think this wrapping is wrong. When user has provided their own connector then there should be any reason to wrap it and add your own tls.