PEP 8: Update a Wikipedia link (#3552)

Author: Rnbsov

peps/pep-0008.rst

@@ -1631,7 +1631,7 @@ References
 
 .. [3] Donald Knuth's *The TeXBook*, pages 195 and 196.
 
-.. [4] http://www.wikipedia.com/wiki/CamelCase
+.. [4] http://www.wikipedia.com/wiki/Camel_case
 
 .. [5] Typeshed repo
    https://github.com/python/typeshed