[FL-2132] IRDA: fix crush in Saved Remote (OK + back) (#894)

Pressing Back button before releasing OK on Saved Remote scene
freezes application, because it doesn't expect that button is
pressed when leaving Saved Remote scene.

Issue: 893

applications/irda/scene/irda-app-scene-remote.cpp

@@ -115,8 +115,10 @@ bool IrdaAppSceneRemote::on_event(IrdaApp* app, IrdaAppEvent* event) {
             break;
         }
     } else if(event->type == IrdaAppEvent::Type::Back) {
+        if(!button_pressed) {
             app->search_and_switch_to_previous_scene(
                 {IrdaApp::Scene::Start, IrdaApp::Scene::RemoteList});
+        }
     } else {
         consumed = false;
     }