Fix HiDPI issue of sample track window

Fix one of the HiDPI issues of the sample track window by removing the
hard coded font size of the name line edit.

src/gui/SampleTrackWindow.cpp

@@ -74,7 +74,6 @@ SampleTrackWindow::SampleTrackWindow(SampleTrackView * tv) :
 
 	// setup line edit for changing sample track name
 	m_nameLineEdit = new QLineEdit;
-	m_nameLineEdit->setFont(pointSize<9>(m_nameLineEdit->font()));
 	connect(m_nameLineEdit, SIGNAL(textChanged(const QString&)),
 				this, SLOT(textChanged(const QString&)));