updating links for #3244 (#3418)

free-programming-books.md

@@ -227,7 +227,6 @@
 * [Bitsavers.org](http://bitsavers.trailing-edge.com)
 * [Bookboon: IT & Programming](http://bookboon.com/en/it-programming-ebooks) Cookie required. (email address *requested*, not required)
 * [Cheat Sheets (Free)](https://dzone.com/refcardz)
-* [Codingus](http://codingus.blogspot.in)
 * [conceptf1.blogspot.com](http://conceptf1.blogspot.com/2013/11/list-of-freely-available-programming.html)
 * [Free Smalltalk Books, collected by Stéphane Ducasse](http://stephane.ducasse.free.fr/FreeBooks.html)
 * [Free Tech Books](http://www.freetechbooks.com)
@@ -683,7 +682,6 @@ Kerridge (PDF) (email address *requested*, not required)
 
 #### Regular Expressions
 
-* [Learn Regex The Hard Way](http://regex.learncodethehardway.org/book/) - Zed. A. Shaw
 * [RexEgg](http://www.rexegg.com)
 * [The 30 Minute Regex Tutorial](http://www.codeproject.com/Articles/9099/The-Minute-Regex-Tutorial) - Jim Hollenhorst
 * [The Bastards Book of Regular Expressions: Finding Patterns in Everyday Text](https://leanpub.com/bastards-regexes) - Dan Nguyen  *(Leanpub account or valid email requested)*