Theming: Fix regression in ComboBox label

The opacity is set to 0.8 if disabled (Not if enabled).

Change-Id: I7016a083f71c700de68444a62e97d5dee4b733e7
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>

src/plugins/coreplugin/manhattanstyle.cpp

@@ -745,7 +745,7 @@ void ManhattanStyle::drawControl(ControlElement element, const QStyleOption *opt
                     painter->setPen(QColor(0, 0, 0, 70));
                     painter->drawText(editRect.adjusted(1, 0, -1, 0), Qt::AlignLeft | Qt::AlignVCenter, text);
                 }
-                if (option->state & State_Enabled)
+                if (!option->state & State_Enabled)
                     painter->setOpacity(0.8);
                 painter->setPen(creatorTheme()->color(Theme::ComboBoxTextColor));
                 painter->drawText(editRect.adjusted(1, 0, -1, 0), Qt::AlignLeft | Qt::AlignVCenter, text);