AutomatableModel: made member variables private again

As of commit dd28a654b5 some member
variables were made protected without any actual requirement for it.
Revert the part of the commit.

include/AutomatableModel.h

@@ -225,9 +225,6 @@ protected:
 
 	float fittedValue( float _value ) const;
 
-	float m_minValue;
-	float m_maxValue;
-	float m_value;
 
 private:
 	void linkModel( AutomatableModel * _model );
@@ -235,7 +232,10 @@ private:
 
 
 	DataType m_dataType;
+	float m_value;
 	float m_initValue;
+	float m_minValue;
+	float m_maxValue;
 	float m_step;
 	float m_range;