Fix camera tilting (some debug left-over broke it).

src/graphics/camera.cpp

@@ -556,7 +556,6 @@ void Camera::positionCamera(float dt, float above_kart, float cam_angle,
         // Rotate the up vector (0,1,0) by the rotation ... which is just column 1
         Vec3 up = m_kart->getTrans().getBasis().getColumn(1);
         float f = 0.04f;  // weight for new up vector to reduce shaking
-        f = 0;
         m_camera->setUpVector(f      * up.toIrrVector() +
             (1.0f - f) * m_camera->getUpVector());
     }   // kart && !flying