remove unused boolean isExecuted variable

Framework/API/inc/MantidAPI/Algorithm.h

@@ -463,7 +463,6 @@ private:
 
   std::atomic<ExecutionState> m_executionState; ///< the current execution state
   std::atomic<ResultState> m_resultState;       ///< the current result State
-  bool m_isExecuted;                            ///< Algorithm is executed flag
   bool m_isChildAlgorithm;      ///< Algorithm is a child algorithm
   bool m_recordHistoryForChild; ///< Flag to indicate whether history should be
                                 /// recorded. Applicable to child algs only

Framework/API/src/Algorithm.cpp

@@ -99,7 +99,7 @@ Algorithm::Algorithm()
       m_log("Algorithm"), g_log(m_log), m_groupSize(0), m_executeAsync(nullptr),
       m_notificationCenter(nullptr), m_progressObserver(nullptr),
       m_executionState(ExecutionState::Uninitialized),
-      m_resultState(ResultState::NotFinished), m_isExecuted(false),
+      m_resultState(ResultState::NotFinished),
       m_isChildAlgorithm(false), m_recordHistoryForChild(false),
       m_alwaysStoreInADS(true), m_runningAsync(false), m_rethrow(false),
       m_isAlgStartupLoggingEnabled(true), m_startChildProgress(0.),