Codechange: use default dtor instead of empty (#10826)

src/fileio_func.h

@@ -39,7 +39,7 @@ protected:
 	Subdirectory subdir; ///< The current sub directory we are searching through
 public:
 	/** Destruct the proper one... */
-	virtual ~FileScanner() {}
+	virtual ~FileScanner() = default;
 
 	uint Scan(const char *extension, Subdirectory sd, bool tars = true, bool recursive = true);
 	uint Scan(const char *extension, const std::string &directory, bool recursive = true);