Fix memory leak, delete EditorConfigurationPrivate

Change-Id: I23869f5669bf06b599454702b45d2b3140252935
Reviewed-by: Leandro Melo <leandro.melo@nokia.com>

src/plugins/projectexplorer/editorconfiguration.cpp

@@ -118,6 +118,7 @@ EditorConfiguration::EditorConfiguration() : d(new EditorConfigurationPrivate)
 EditorConfiguration::~EditorConfiguration()
 {
     qDeleteAll(d->m_languageCodeStylePreferences.values());
+    delete d;
 }
 
 bool EditorConfiguration::useGlobalSettings() const