fixing duplication of an id (zalando#260)

Author: maxim-tschumak

chapters/data-formats.adoc

@@ -11,7 +11,7 @@ since it would allow for future extension. This also applies for
 collection resources where one naturally would assume an array. See <<160>> for
 an example.
 
-[#166]
+[#167]
 == {MAY} Use non JSON Media Types for Binary Data or Alternative Content Representations
 
 Other media types may be used in following cases: * Transferring binary