Add missing overrides

Change-Id: I7e27a273044542537423c8f4b9ab5235c3fabc22
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/subversion/subversionclient.cpp

@@ -175,7 +175,7 @@ public:
     void setChangeNumber(int changeNumber);
 
 protected:
-    void reload();
+    void reload() override;
 
 private slots:
     void slotTextualDiffOutputReceived(const QString &contents);