A+C: Berengar Lehr (individual CLA)

Was added to CONTRIBUTORS file in:

changeset:   7092:638ad4d7d280
user:        Berengar Lehr <Berengar.Lehr@gmx.de>
date:        Tue Jan 11 20:51:35 2011 -0500
summary:     crypto: add twofish package

but never added to AUTHORS file.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5532107

AUTHORS

@@ -30,6 +30,7 @@ Aron Nopanen <aron.nopanen@gmail.com>
 Arvindh Rajesh Tamilmani <art@a-30.net>
 Ben Olive <sionide21@gmail.com>
 Benny Siegert <bsiegert@gmail.com>
+Berengar Lehr <berengar.lehr@gmx.de>
 Bobby Powers <bobbypowers@gmail.com>
 Caine Tighe <arctanofyourface@gmail.com>
 Charles L. Dorian <cldorian@gmail.com>