ProjectExplorer: Remove unnecessary visual gap in runsettings

Some Run Settings widgets had an unnecessary 2-pixel gap on the top.
This removes it.

Change-Id: Ie958940e6d2301ca0e51d93ddca9dc77f9ccaed1
Reviewed-by: Cristian Adam <cristian.adam@qt.io>

src/plugins/projectexplorer/runsettingspropertiespage.cpp

@@ -496,7 +496,7 @@ void RunSettingsWidget::addRunControlWidgets()
 
 void RunSettingsWidget::addSubWidget(QWidget *widget, QLabel *label)
 {
-    widget->setContentsMargins(0, 2, 0, 0);
+    widget->setContentsMargins({});
 
     QFont f = label->font();
     f.setBold(true);