[libxslt] xsltproc: Fix unused variable warning

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 1c0b183dfd3ef17c24d11e1340d3903a710756e9
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Tue Sep 6 14:40:12 2022 +0200

    xsltproc: Fix unused variable warning

 xsltproc/xsltproc.c | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/xsltproc/xsltproc.c b/xsltproc/xsltproc.c
index 7edcc536..a2882359 100644
--- a/xsltproc/xsltproc.c
+++ b/xsltproc/xsltproc.c
@@ -55,7 +55,9 @@
 #include <sys/timeb.h>
 #endif
 
+#ifdef LIBXML_DEBUG_ENABLED
 static int debug = 0;
+#endif
 static int repeat = 0;
 static int timing = 0;
 static int dumpextensions = 0;