image_png.h: change name of multiple-inclusion guard to not interfere with <png.h>

Origin: vendor, Debian

diff --git a/image_png.h b/image_png.h
index d290d98f5104d3b6303e5fd4dedeeecae70336d6..4c94cd7b0c69676ab9096f4577e44d49d2de7160 100644 (file)
--- a/image_png.h
+++ b/image_png.h
@@ -21,8 +21,8 @@
 
 */
 
-#ifndef PNG_H
-#define PNG_H
+#ifndef QUAKE_IMAGE_PNG_H
+#define QUAKE_IMAGE_PNG_H
 
 qboolean PNG_OpenLibrary (void);
 void PNG_CloseLibrary (void);