Fix typo in buildall.sh

csharp/buildall.sh

diff --git a/csharp/buildall.sh b/csharp/buildall.sh
index 20fb46b..d903c1c 100755
--- a/csharp/buildall.sh
+++ b/csharp/buildall.sh
@@ -6,7 +6,7 @@
 
 # The rest you can leave intact
 CONFIG=Release
-KEYFILE=../keys/Google.Google.Protobuf.snk  # TODO(jtattermusch): signing!
+KEYFILE=../keys/Google.Protobuf.snk  # TODO(jtattermusch): signing!
 SRC=$(dirname $0)/src
 
 set -ex