QML Live Preview: Apparently, the interresting root object is the last.

Even if we should really care about all of them, the object that is the root
of all the graphical QML item is the usually last.

src/plugins/qmljsinspector/qmljsclientproxy.cpp

@@ -361,7 +361,7 @@ void ClientProxy::contextChanged()
             m_rootObject = QDeclarativeDebugObjectReference();
             emit objectTreeUpdated(m_rootObject);
         } else {
-            m_rootObject = m_contextQuery->rootContext().objects().first();
+            m_rootObject = m_contextQuery->rootContext().objects().last();
         }
 
         delete m_contextQuery;