Fix compiler warning.

src/plugins/texteditor/generichighlighter/manager.cpp

@@ -63,6 +63,10 @@ using namespace Internal;
 Manager::Manager()
 {}
 
+Manager::~Manager()
+{
+}
+
 Manager *Manager::instance()
 {
     static Manager manager;

src/plugins/texteditor/generichighlighter/manager.h

@@ -53,7 +53,8 @@ class HighlightDefinition;
 class Manager : public QObject
 {
     Q_OBJECT
-public:    
+public:
+    virtual ~Manager();
     static Manager *instance();
 
     QString definitionIdByName(const QString &name) const;