remember m_iCurrentStageIndex

stepmania/src/ScreenGameplay.cpp

@@ -401,6 +401,7 @@ void ScreenGameplay::Init()
 			PROFILEMAN->IncrementCoursePlayCount( GAMESTATE->m_pCurCourse, GAMESTATE->m_pCurTrail[p], p );
 
 	STATSMAN->m_CurStageStats.m_Stage = GAMESTATE->GetCurrentStage();
+	STATSMAN->m_CurStageStats.m_iStageIndex = GAMESTATE->m_iCurrentStageIndex;
 	STATSMAN->m_CurStageStats.m_playMode = GAMESTATE->m_PlayMode;
 	STATSMAN->m_CurStageStats.m_pStyle = GAMESTATE->GetCurrentStyle();