InstrumentTrack: set minimum size for save settings button

Set minimum size of 32x32 pixels for an appropriate appearance.

src/tracks/InstrumentTrack.cpp

@@ -1329,6 +1329,7 @@ InstrumentTrackWindow::InstrumentTrackWindow( InstrumentTrackView * _itv ) :
 
 
 	QPushButton* saveSettingsBtn = new QPushButton( embed::getIconPixmap( "project_save" ), QString() );
+	saveSettingsBtn->setMinimumSize( 32, 32 );
 
 	connect( saveSettingsBtn, SIGNAL( clicked() ), this, SLOT( saveSettingsBtnClicked() ) );