Fix so all paths return a value

modules/autonavigation/autonavigationhandler.cpp

@@ -74,6 +74,7 @@ const int AutoNavigationHandler::currentPathSegmentIndex() const {
             return i;
         }
     }
+    return -1;
 }
 
 CameraState AutoNavigationHandler::currentCameraState() {
@@ -91,6 +92,8 @@ void AutoNavigationHandler::updateCamera(double deltaTime) {
 
     const int currentIndex = currentPathSegmentIndex();
 
+    if (currentIndex < 0) return; // no path
+
     if (_stopAtTargets && (currentIndex != _activeSegmentIndex)) {
         _activeSegmentIndex = currentIndex; 
         pausePath();