QmlDesigner.nodeInstances: fix regression

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Change-Id: I02c2a2e741accda4d3f67cbb2a1cf5a12cabafb1
Reviewed-on: http://codereview.qt.nokia.com/484

Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@nokia.com>

src/tools/qmlpuppet/instances/nodeinstanceserver.cpp

@@ -379,7 +379,7 @@ void NodeInstanceServer::setupImports(const QVector<AddImportContainer> &contain
 
 void NodeInstanceServer::setupFileUrl(const QUrl &fileUrl)
 {
-    if (fileUrl.isEmpty()) {
+    if (!fileUrl.isEmpty()) {
         engine()->setBaseUrl(fileUrl);
         m_fileUrl = fileUrl;
     }