include .m in check_copyright.py
diff --git a/src/objective-c/GRPCClient/private/NSError+GRPC.h b/src/objective-c/GRPCClient/private/NSError+GRPC.h
index b7439fa..6183008 100644
--- a/src/objective-c/GRPCClient/private/NSError+GRPC.h
+++ b/src/objective-c/GRPCClient/private/NSError+GRPC.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2014, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without