Qnx: Do not re-validate information on each Qt version manager chance

That's rarely resulting in an actual change, but fairly expensive
and triggered often, even when not actively using Qnx.

Change-Id: I784bc7fa4919bf48711036d655e8246805aa578b
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/qnx/qnxsettingspage.cpp

@@ -484,7 +484,6 @@ static QnxSettingsPagePrivate *dd = nullptr;
 
 // QnxSettingsWidget
 
-
 class ArchitecturesList final : public QWidget
 {
 public:
@@ -594,8 +593,6 @@ QnxSettingsWidget::QnxSettingsWidget()
 
     connect(m_configsCombo, &QComboBox::currentIndexChanged,
             this, &QnxSettingsWidget::updateInformation);
-    connect(QtVersionManager::instance(), &QtVersionManager::qtVersionsChanged,
-            this, &QnxSettingsWidget::updateInformation);
 }
 
 void QnxSettingsWidget::addConfiguration()