doc: update link to book
@@ -69,7 +69,7 @@ without you we would not have been able to collect all the
information that led to the requirements for Elektra.
The LaTeX sources are available [here](https://book.libelektra.org)
-and the compiled book can be downloaded from [here](https://book.libelektra.org/raw/master/book/book.pdf).
+and the compiled book can be downloaded from [here](https://www.libelektra.org/ftp/elektra/publications/raab2017context.pdf).
### Maturing of Plugins
