src: drop 'virtual' from functions marked 'final' or 'override'

Change-Id: Ieb6df864ab82f77b2bee9e83aa0bfa2005715950
Refs: #3857
diff --git a/src/util/dummy-client-face.hpp b/src/util/dummy-client-face.hpp
index 7d661a7..41d843e 100644
--- a/src/util/dummy-client-face.hpp
+++ b/src/util/dummy-client-face.hpp
@@ -111,7 +111,7 @@
   void
   enableRegistrationReply();
 
-  virtual void
+  void
   doProcessEvents(const time::milliseconds& timeout, bool keepThread) override;
 
 public: