Fix Linux Inside link (#5407)

books/free-programming-books.md

@@ -2033,7 +2033,7 @@ Kerridge (PDF) (email address *requested*, not required)
 * [Linux Device Drivers, Third Edition](http://lwn.net/Kernel/LDD3/) - Jonathan Corbet, Alessandro Rubini, and Greg Kroah-Hartman
 * [Linux from Scratch](http://www.linuxfromscratch.org/lfs/view/stable/)
 * [Linux Fundamentals](http://linux-training.be/linuxfun.pdf) - Paul Cobbaut (PDF)
-* [Linux Inside](https://www.gitbook.com/book/0xax/linux-insides/details)
+* [Linux Inside](https://0xax.gitbooks.io/linux-insides/content/index.html)
 * [Linux Kernel in a Nutshell](http://www.kroah.com/lkn/)
 * [Linux Newbie Administrator Guide](http://lnag.sourceforge.net)
 * [Linux Security for Beginners](http://www.linuxtopia.org/LinuxSecurity/index.html)