fixing compilation and link option when configuring with --without-valid

* debugXML.c relaxng.c valid.c xinclude.c xmllint.c xmlreader.c:
  fixing compilation and link option when configuring with
  --without-valid should fix #135309
Daniel
diff --git a/xinclude.c b/xinclude.c
index 4cd762f..9247632 100644
--- a/xinclude.c
+++ b/xinclude.c
@@ -132,6 +132,7 @@
 		    msg, (const char *) extra);
 }
 
+#if 0
 /**
  * xmlXIncludeWarn:
  * @ctxt: the XInclude context
@@ -150,6 +151,7 @@
 		    (const char *) extra, NULL, NULL, 0, 0,
 		    msg, (const char *) extra);
 }
+#endif
 
 /**
  * xmlXIncludeGetProp: