If JPEGXL_MAJOR_VERSION isn't define, define to zero.

It wasn't in v0.6.x, which is packaged by Haiku.

If JPEGXL_MAJOR_VERSION isn't define, define to zero.
de964690 · Deucе · d4d05239 · de964690
Commit de964690 authored 2 months ago by Deucе
--- a/src/syncterm/libjxl.h
+++ b/src/syncterm/libjxl.h
@@ -12,6 +12,10 @@
 #include <jxl/resizable_parallel_runner.h>
 #endif

+#ifndef JPEGXL_MAJOR_VERSION
+#define JPEGXL_MAJOR_VERSION 0
+#endif
+
 enum JxlStatus {
 	JXL_STATUS_UNINITIALIZED,
 	JXL_STATUS_FAILED,