Fix Qt 6 definition of macro ‘Q_DECLARE_MOVABLE_CONTAINER’

adding #include <QHash>

+ code fail to compile if it uses deprecated APIs.
=> see .pro file

sources/undocommand/rotateselectioncommand.h

@@ -1,17 +1,17 @@
 /*
 	Copyright 2006-2020 The QElectroTech Team
 	This file is part of QElectroTech.
-	
+
 	QElectroTech is free software: you can redistribute it and/or modify
 	it under the terms of the GNU General Public License as published by
 	the Free Software Foundation, either version 2 of the License, or
 	(at your option) any later version.
-	
+
 	QElectroTech is distributed in the hope that it will be useful,
 	but WITHOUT ANY WARRANTY; without even the implied warranty of
 	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 	GNU General Public License for more details.
-	
+
 	You should have received a copy of the GNU General Public License
 	along with QElectroTech.  If not, see <http://www.gnu.org/licenses/>.
 */
@@ -20,6 +20,7 @@
 
 #include <QUndoCommand>
 #include <QPointer>
+#include <QHash>
 
 class Diagram;
 class ConductorTextItem;
@@ -35,16 +36,16 @@ class RotateSelectionCommand : public QUndoCommand
 		RotateSelectionCommand(Diagram *diagram, qreal angle=90, QUndoCommand *parent=nullptr);
 		void undo() override;
 		void redo() override;
-		
+
 		bool isValid();
-	
+
 	private:
 		Diagram *m_diagram =nullptr;
-		
+
 		QList<QPointer<ConductorTextItem>> m_cond_text;
 		QHash<ConductorTextItem *, bool> m_rotate_by_user;
 		QList<QPropertyUndoCommand*> m_undo;
-		
+
 };
 
 #endif // ROTATESELECTIONCOMMAND_H