bugfix(ghostobject): Readd null check for 3DScene in W3DRenderObjectSnapshot::addToScene to prevent crash in headless replay playback (TheSuperHackers#2133)

Author: Skyaero42

Generals/Code/GameEngineDevice/Source/W3DDevice/GameLogic/W3DGhostObject.cpp

@@ -153,7 +153,7 @@ void W3DRenderObjectSnapshot::update(RenderObjClass *robj, DrawableInfo *drawInf
 // ------------------------------------------------------------------------------------------------
 Bool W3DRenderObjectSnapshot::addToScene(void)
 {
-	if (!m_robj->Is_In_Scene())
+	if (W3DDisplay::m_3DScene != nullptr && !m_robj->Is_In_Scene())
 	{
 		W3DDisplay::m_3DScene->Add_Render_Object(m_robj);
 		return true;

GeneralsMD/Code/GameEngineDevice/Source/W3DDevice/GameLogic/W3DGhostObject.cpp

@@ -157,7 +157,7 @@ void W3DRenderObjectSnapshot::update(RenderObjClass *robj, DrawableInfo *drawInf
 // ------------------------------------------------------------------------------------------------
 Bool W3DRenderObjectSnapshot::addToScene(void)
 {
-	if (!m_robj->Is_In_Scene())
+	if (W3DDisplay::m_3DScene != nullptr && !m_robj->Is_In_Scene())
 	{
 		W3DDisplay::m_3DScene->Add_Render_Object(m_robj);
 		return true;