Add warning to login_sso

src/matrix.rs

@@ -63,6 +63,8 @@ impl LoginChoice {
     }
 
     async fn login_sso(client: &Client, idp: Option<IdentityProvider>) -> anyhow::Result<Client> {
+        println!("Warning! SSO is a work in progress. Do not expect it to work.");
+        
         let redirect_url = String::new();
 
         let token = if let Some(idp) = idp {