fixing bug 59732, simple but allocates a new error code. Daniel

* include/libxml/xmlerror.h SAX.c: fixing bug 59732, simple
  but allocates a new error code.
Daniel
diff --git a/SAX.c b/SAX.c
index 4dab41e..5466c01 100644
--- a/SAX.c
+++ b/SAX.c
@@ -971,6 +971,8 @@
 	      "Validation failed: no DTD found !\n");
 	}
 	ctxt->validate = 0;
+	ctxt->valid = 0;
+	ctxt->errNo = XML_ERR_NO_DTD;
     }