Fixed copyright symbol in testgles2 program.
diff --git a/test/testgles2.c b/test/testgles2.c
index 58a46ac..5acc13d 100644
--- a/test/testgles2.c
+++ b/test/testgles2.c
@@ -1,5 +1,5 @@
/*
- Copyright (r) 1997-2017 Sam Lantinga <slouken@libsdl.org>
+ Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org>
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages