Make TlsConnector::new + TlsAcceptor::new take references to the config

[rukai]

TlsConnector::new and TlsAcceptor::new both take a TlsConnectorConfig/TlsAcceptorConfig but they could easily take a &TlsConnectorConfig/&TlsAcceptorConfig instead.
So lets do that.

Once changed we will need to find all the locations that call new and swap the Clone::clone() with an Option::as_ref:

-        let tls = self.tls.clone().map(TlsConnector::new).transpose()?;
+        let tls = self.tls.as_ref().map(TlsConnector::new).transpose()?;

Here, Option::as_ref takes an &Option<TlsConnectorConfig> and returns it as Option<&TlsConnector>.
This is important because we need the value that the function in .map(..) is given to be &TlsConnector instead of TlsConnector.

If this were a code path that every message took this would be a nice performance improvement.
In reality this wont make shotover any faster since the code path only occurs during shotover's initialization, so it will only make initialization a tiny bit faster.
But its a nice isolated introduction to working with borrows vs clones and makes the code follow patterns used in the rest of the codebase.