remove mqtt example, instantiate scheduler and activate plugins in base activation method

src/Sprocket.cpp

@@ -13,15 +13,14 @@ Sprocket* Sprocket::init(SprocketConfig cfg){
     delay(cfg.startupDelay);
     Serial.begin(cfg.serialBaudRate);
     SPIFFS.begin();
-    scheduler = new Scheduler();
     return this;
 }
 Sprocket* Sprocket::activate() {
+    scheduler = new Scheduler();
+    activatePlugins(scheduler);
     return activate(scheduler);
 }
-Sprocket* Sprocket::activate(Scheduler* scheduler) {
-    // setup plugins
-    activatePlugins(scheduler);
+Sprocket* Sprocket::activate(Scheduler* s) {
     return this;
 }