clang-tidy fix: [modernize-use-override]

prefer using 'override' or (rarely) 'final' instead of 'virtual'
[modernize-use-override]

server/loadConfig.cpp

@@ -42,12 +42,9 @@ class ParseException : public virtual std::exception
 public:
   ParseException(std::string message) : message(std::move(message)){};
 
-  virtual ~ParseException() = default;
+  ~ParseException() override = default;
 
-  virtual const char *what() const noexcept
-  {
-    return message.c_str();
-  };
+  const char *what() const noexcept override { return message.c_str(); };
 
   const std::string &getMessage() const
   {

server/transport/websocket/WebSocketTransport.cpp

@@ -56,8 +56,7 @@ class configuration_exception : public std::exception
     this->message = message;
   }
 
-  virtual const char *what() const _GLIBCXX_USE_NOEXCEPT
-  {
+  const char *what() const _GLIBCXX_USE_NOEXCEPT override {
     return message.c_str();
   }
 

test/server_duplicate_requests.cpp

@@ -38,7 +38,7 @@ class ClientHandler : public F
 public:
   ClientHandler() : F() {};
 
-  virtual ~ClientHandler() = default;
+  ~ClientHandler() override = default;
 
 protected:
   void check_create_duplicate_requests_call ();

test/server_events_test.cpp

@@ -35,7 +35,7 @@ class ClientHandler : public F
 public:
   ClientHandler() : F() {};
 
-  ~ClientHandler() = default;
+  ~ClientHandler() override = default;
 
 protected:
   void check_not_duplicated_event ();

test/server_json_session.cpp

@@ -39,7 +39,7 @@ class ClientHandler : public F
 public:
   ClientHandler() : F() {};
 
-  virtual ~ClientHandler() = default;
+  ~ClientHandler() override = default;
 
 protected:
   void check_create_pipeline_call ();

test/server_json_test.cpp

@@ -39,7 +39,7 @@ class ClientHandler : public F
                              GST_DEFAULT_NAME);
   };
 
-  ~ClientHandler() = default;
+  ~ClientHandler() override = default;
 
 protected:
   void check_error_call ();