fix(zone): remove debugger statement

Author: robwormald

lib/zone.ts

@@ -318,7 +318,7 @@ interface ZoneSpec {
 
   /**
    * Notifies of changes to the task queue empty status.
-   * 
+   *
    * @param parentZoneDelegate Dalegate which performs the parent [ZoneSpec] operation.
    * @param currentZone The current [Zone] where the current interceptor has beed declared.
    * @param targetZone The [Zone] which originally received the request.