UI: Reset sources list manually on first load

UI/source-tree.hpp

@@ -149,6 +149,7 @@ public:
 	explicit SourceTree(QWidget *parent = nullptr);
 
 	inline bool IgnoreReorder() const {return ignoreReorder;}
+	inline void Reset() {GetStm()->SceneChanged();}
 	inline void Clear() {GetStm()->Clear();}
 
 	inline void Add(obs_sceneitem_t *item) {GetStm()->Add(item);}

UI/window-basic-main.cpp

@@ -1515,6 +1515,7 @@ void OBSBasic::OBSInit()
 		ProfileScope("OBSBasic::Load");
 		disableSaving--;
 		Load(savePath);
+		ui->sources->Reset();
 		disableSaving++;
 	}
 #endif