debian/copyright: Code in this repository is under BSD-2-Clause

The license is not a 3-clause BSD, but a 2-clause BSD.  Couldn't
find any trace to a 3rd clause anywhere.

Change-Id: I4f908ce4f670e062e6808ac7966d0e52bfe6b4f9
diff --git a/debian/copyright b/debian/copyright
index 2eef07a..0494a0a 100644
--- a/debian/copyright
+++ b/debian/copyright
@@ -4,17 +4,17 @@
 
 Files: *
 Copyright: 2005-2014 Lev Walkin <vlm@lionet.info>
-License: BSD-3-Clause
+License: BSD-2-Clause
 
 Files: src/xer_support.c
 Copyright: 2003,2004 X/IO Labs, xiolabs.com.
            2003,2004,2005 Lev Walkin <vlm@lionet.info>.
-License: BSD-3-Clause
+License: BSD-2-Clause
 
 Files: include/asn1c/xer_support.h
 Copyright: 2003,2004 X/IO Labs, xiolabs.com
            2003,2004 Lev Walkin <vlm@lionet.info>
-License: BSD-3-Clause
+License: BSD-2-Clause
 
 Files: src/asn1helpers.c
 Copyright: 2014-2015 by Harald Welte <laforge@gnumonks.org>