[gnome-bluetooth] tests: Add license header

[Bastien Nocera <hadess src gnome org>]

commit f0f94273b3fe61ed6e2d84e5874048d760f165c4
Author: Bastien Nocera <hadess hadess net>
Date:   Wed Feb 16 09:20:50 2022 +0100

    tests: Add license header

 tests/test-bluetooth-utils.c | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/tests/test-bluetooth-utils.c b/tests/test-bluetooth-utils.c
index 67297688..2dfdea60 100644
--- a/tests/test-bluetooth-utils.c
+++ b/tests/test-bluetooth-utils.c
@@ -1,3 +1,9 @@
+/*
+ * Copyright (C) 2021 Bastien Nocera <hadess hadess net>
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
 #include <locale.h>
 #include <bluetooth-utils.c>