don't use blockStatement anymore

libs/microbit/control.cpp

@@ -151,7 +151,7 @@ namespace control {
      * Raises an event in the event bus.
      */
     //% weight=20 blockGap=8 blockId="control_on_event" block="on event|from %src=control_event_source|with value %value=control_event_value" 
-    //% blockExternalInputs=1 blockStatement=1
+    //% blockExternalInputs=1
     void onEvent(int src, int value, Action handler) { 
         registerWithDal(src, value, handler);
     }

libs/microbit/shims.d.ts

@@ -340,7 +340,7 @@ declare namespace control {
      * Raises an event in the event bus.
      */
     //% weight=20 blockGap=8 blockId="control_on_event" block="on event|from %src=control_event_source|with value %value=control_event_value" 
-    //% blockExternalInputs=1 blockStatement=1 shim=control::onEvent
+    //% blockExternalInputs=1 shim=control::onEvent
     function onEvent(src: number, value: number, handler: () => void): void;
 }