rm const getter

GUI/Model/Device/InstrumentItems.h

@@ -179,7 +179,6 @@ public:
     const ICoordSystem* createCoordSystem() const override;
 
     AxisProperty& zAxis() { return m_zAxis; }
-    const AxisProperty& zAxis() const { return m_zAxis; }
 
     bool isExpandParameters() const { return m_expandParameters; }
     void setExpandParameters(bool b) { m_expandParameters = b; }