no need to lock twice on siblings

app/node/processor/renderer/rendererprocessthread.h

@@ -36,7 +36,7 @@ public:
                         const olive::PixelFormat& format,
                         const olive::RenderMode& mode);
 
-  bool Queue(const NodeDependency &dep, bool wait);
+  bool Queue(const NodeDependency &dep, bool wait, bool sibling);
 
 public slots:
   virtual void Cancel() override;
@@ -62,6 +62,8 @@ private:
 
   QAtomicInt cancelled_;
 
+  bool sibling_;
+
 };
 
 using RendererProcessThreadPtr = std::shared_ptr<RendererProcessThread>;