Fix crash in iButton notifications routine (#2074)

* iButton: send notifications less strictly
* iButton: set notification callback earlier

lib/one_wire/ibutton/ibutton_worker.c

@@ -131,7 +131,9 @@ void ibutton_worker_switch_mode(iButtonWorker* worker, iButtonWorkerMode mode) {
 
 void ibutton_worker_notify_emulate(iButtonWorker* worker) {
     iButtonMessage message = {.type = iButtonMessageNotifyEmulate};
-    furi_check(furi_message_queue_put(worker->messages, &message, 0) == FuriStatusOk);
+    // we're running in an interrupt context, so we can't wait
+    // and we can drop message if queue is full, that's ok for that message
+    furi_message_queue_put(worker->messages, &message, 0);
 }
 
 void ibutton_worker_set_key_p(iButtonWorker* worker, iButtonKey* key) {

lib/one_wire/ibutton/ibutton_worker_modes.c

@@ -222,8 +222,8 @@ void ibutton_worker_emulate_dallas_start(iButtonWorker* worker) {
     memcpy(device_id, key_id, key_size);
 
     onewire_slave_attach(worker->slave, worker->device);
-    onewire_slave_start(worker->slave);
     onewire_slave_set_result_callback(worker->slave, onewire_slave_callback, worker);
+    onewire_slave_start(worker->slave);
 }
 
 void ibutton_worker_emulate_dallas_stop(iButtonWorker* worker) {