fix copyrights in server_context

src/cpp/server/server_context.cc

diff --git a/src/cpp/server/server_context.cc b/src/cpp/server/server_context.cc
index 5be2271..b3a74c7 100644
--- a/src/cpp/server/server_context.cc
+++ b/src/cpp/server/server_context.cc
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without