$OpenBSD: patch-src_include_OpenImageIO_strutil_h,v 1.1 2019/11/21 17:49:57 cwen Exp $

Add missing header for ports-gcc

Index: src/include/OpenImageIO/strutil.h
--- src/include/OpenImageIO/strutil.h.orig
+++ src/include/OpenImageIO/strutil.h
@@ -43,6 +43,7 @@
 
 #include <string>
+#include <cstdarg>
 #include <cstdio>
 #include <vector>
 #include <map>
 
