PianoRoll: switch back to draw note after pasting notes

When pasing notes via Ctrl+V somehow the edit-tool was left in an
undefined state. Therefore explicitely switch back to draw mode so
user can move pasted notes (closes #2808607).

Signed-off-by: Tobias Doerffel <tobias.doerffel@gmail.com>

src/gui/piano_roll.cpp

@@ -3411,6 +3411,8 @@ void pianoRoll::pasteNotes( void )
 		// we only have to do the following lines if we pasted at
 		// least one note...
 		engine::getSong()->setModified();
+		m_ctrlMode = ModeDraw;
+		m_drawButton->setChecked( true );
 		update();
 		engine::getSongEditor()->update();
 	}