Devicemanager: Do not ruin device settings when closing optionspage

Change-Id: I3684422f9d41eba3bda8532c58242eca7edef67b
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/plugins/projectexplorer/devicesupport/devicemanager.cpp

@@ -135,6 +135,8 @@ void DeviceManager::copy(const DeviceManager *source, DeviceManager *target, boo
 
 void DeviceManager::save()
 {
+    if (d->clonedInstance == this)
+        return;
     QVariantMap data;
     data.insert(QLatin1String(DeviceManagerKey), toMap());
     d->writer->save(data, Core::ICore::mainWindow());
@@ -342,7 +344,8 @@ DeviceManager::DeviceManager(bool isInstance) : d(new DeviceManagerPrivate)
 
 DeviceManager::~DeviceManager()
 {
-    delete d->writer;
+    if (d->clonedInstance != this)
+        delete d->writer;
     delete d;
 }