tokio-xmpp: simplify examples by requiring specific TLS features

tokio-xmpp/examples/echo_component.rs

@@ -6,30 +6,12 @@ use xmpp_parsers::jid::Jid;
 use xmpp_parsers::message::{Lang, Message, MessageType};
 use xmpp_parsers::presence::{Presence, Show as PresenceShow, Type as PresenceType};
 
-#[cfg(feature = "rustls-any-backend")]
-use tokio_xmpp::rustls;
 use tokio_xmpp::{connect::DnsConfig, Component};
 
-#[cfg(all(
-    feature = "rustls-any-backend",
-    not(any(feature = "aws_lc_rs", feature = "ring"))
-))]
-compile_error!("using rustls (e.g. via the ktls feature) needs an enabled rustls backend feature (either aws_lc_rs or ring).");
-
 #[tokio::main]
 async fn main() {
     env_logger::init();
 
-    #[cfg(all(feature = "aws_lc_rs", not(feature = "ring")))]
-    rustls::crypto::aws_lc_rs::default_provider()
-        .install_default()
-        .expect("failed to install rustls crypto provider");
-
-    #[cfg(all(feature = "ring"))]
-    rustls::crypto::ring::default_provider()
-        .install_default()
-        .expect("failed to install rustls crypto provider");
-
     let args: Vec<String> = args().collect();
     if args.len() < 3 || args.len() > 4 {
         println!("Usage: {} <jid> <password> [server:port]", args[0]);