Fix broken link in C++ resource, check_urls=free-programming-books.md (#5052)

free-programming-books.md

@@ -1122,7 +1122,7 @@ Kerridge (PDF) (email address *requested*, not required)
 
 * [C++ Annotations](https://fbb-git.gitlab.io/cppannotations/) - Frank B. Brokken (HTML, PDF)
 * [C++ Core Guidelines](https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md) - Editors: Bjarne Stroustrup, Herb Sutter
-* [C++ GUI Programming With Qt 3](http://www.computer-books.us/cpp_0010.php) - Jasmin Blanchette, Mark Summerfield
+* [C++ GUI Programming With Qt 3](https://ptgmedia.pearsoncmg.com/images/0131240722/downloads/blanchette_book.pdf) - Jasmin Blanchette, Mark Summerfield (PDF)
 * [C++ Language](http://www.cplusplus.com/doc/tutorial/)
 * [C++ Notes for Professionals](https://goalkicker.com/CPlusPlusBook) - Compiled from StackOverflow Documentation (PDF)
 * [C++ Succinctly, Syncfusion](https://www.syncfusion.com/resources/techportal/ebooks/cplusplus) (PDF, Kindle) (email address *requested*, not required)