fix SonarPen for iOS

src/app.h

@@ -22,6 +22,7 @@
 #if defined(__OBJC__) && defined(__IOS__)
 #import <Foundation/Foundation.h>
 #import "GameViewController.h"
+#import "AppDelegate.h"
 #endif
 
 #if defined(__OBJC__) && defined(__OSX__)
@@ -152,6 +153,7 @@ public:
     
 #if defined(__IOS__) && defined(__OBJC__)
     GameViewController* ios_view;
+    AppDelegate* ios_app;
 #elif defined(__OSX__) && defined(__OBJC__)
     View* osx_view;
     AppOSX* osx_app;