Update free-programming-books.md (#4757)

free-programming-books.md

@@ -1460,7 +1460,7 @@ Kerridge (PDF) (email address *requested*, not required)
 * [Real World Haskell](http://book.realworldhaskell.org)
 * [Speeding Through Haskell](http://www.sthaskell.com)
 * [What I Wish I Knew When Learning Haskell](http://dev.stephendiehl.com/hask/) - Stephen Diehl (PDF)
-* [Wise Man's Haskell](https://anchpop.github.io/wise_mans_haskell/) - Andre Popovitch
+* [Wise Man's Haskell](https://github.com/anchpop/wise_mans_haskell/blob/master/book.md#preface) - Andre Popovitch
 * [Yet Another Haskell Tutorial](http://hal3.name/docs/daume02yaht.pdf) (PDF)