sphinx-key: remove tls feature

not needed any longer, mqtts no longer a memory problem
to specify mqtt vs mqtts, add the mqtt[s]:// to the broker url

sphinx-key/Cargo.toml

@@ -7,7 +7,7 @@ version      = "0.1.0"
 resolver     = "2"
 
 [features]
-default    = ["std", "tls"]
+default    = ["std"]
 no_persist = []
 pingpong   = []
 std        = ["sphinx-signer"]

sphinx-key/src/conn/mqtt.rs

@@ -29,10 +29,7 @@ pub fn make_client(
         ..Default::default()
     };
 
-    if cfg!(feature = "tls") {
     conf.crt_bundle_attach = Some(esp_idf_svc::sys::esp_crt_bundle_attach);
-    }
-
     let mut mqtturl = broker.to_string();
     if !(mqtturl.starts_with("mqtt://") || mqtturl.starts_with("mqtts://")) {
         let scheme = if mqtturl.contains("8883") {