Fixed memory leak in AudioListener and Camera

gameplay/src/AudioListener.cpp

@@ -102,7 +102,7 @@ Camera* AudioListener::getCamera() const
 
 void AudioListener::setCamera(Camera* camera)
 {
-    if (!camera || _camera == camera)
+    if (_camera == camera)
         return;
 
     // Disconnect our current camera.

gameplay/src/Camera.cpp

@@ -37,6 +37,7 @@ Camera::Camera(float zoomX, float zoomY, float aspectRatio, float nearPlane, flo
 
 Camera::~Camera()
 {
+    SAFE_DELETE(_listeners);
 }
 
 Camera* Camera::createPerspective(float fieldOfView, float aspectRatio, float nearPlane, float farPlane)