Qmake: Set a rootProjectNode early.

This one covers the time between a QmakeProject being constructed and
has its settings read or is being parsed.

Change-Id: I64d6a9d39b1e188d2af10c58135ab9174af8d701
Reviewed-by: Christian Stenger <christian.stenger@theqtcompany.com>
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/qmakeprojectmanager/qmakeproject.cpp

@@ -307,6 +307,8 @@ QmakeProject::QmakeProject(QmakeManager *manager, const QString &fileName) :
     m_asyncUpdateTimer.setInterval(3000);
     connect(&m_asyncUpdateTimer, &QTimer::timeout, this, &QmakeProject::asyncUpdate);
 
+    setRootProjectNode(new QmakeProFileNode(this, projectFilePath()));
+
     connect(BuildManager::instance(), &BuildManager::buildQueueFinished,
             this, &QmakeProject::buildFinished);
 
@@ -356,8 +358,6 @@ Project::RestoreResult QmakeProject::fromMap(const QVariantMap &map, QString *er
 
     projectManager()->registerProject(this);
 
-    setRootProjectNode(new QmakeProFileNode(this, projectFilePath()));
-
     // On active buildconfiguration changes, reevaluate the .pro files
     m_activeTarget = activeTarget();
     if (m_activeTarget) {