blockchain is not a language. the dummies book should be is subjects list

Author: eshellman

Diff for: books/free-programming-books-langs.md

@@ -26,7 +26,6 @@ That section got so big, we decided to split it into its own file, the [BY SUBJE
 * [Bash](#bash)
 * [Basic](#basic)
 * [BETA](#beta)
-* [Blockchain](#blockchain)
 * [C](#c)
 * [C#](#c-sharp)
 * [C++](#cpp)
@@ -404,11 +403,6 @@ That section got so big, we decided to split it into its own file, the [BY SUBJE
 * [Object-Oriented Programming in the BETA Programming Language](https://beta.cs.au.dk/Books/) - Ole Lehrmann Madsen, Birger Møller-Pedersen, Kristen Nygaard
 
 
-### Blockchain
-
-* [Blockchain for Dummies](https://www.ibm.com/downloads/cas/36KBMBOG) - Manav Gupta (PDF)
-
-
 ### C
 
 * [256-Color VGA Programming in C](http://www.brackeen.com/vga/) - David Brackeen