avoid an include problem if #include <libxml/xmlerror.h> happens first in

* include/libxml/xmlerror.h: avoid an include problem if
  #include <libxml/xmlerror.h> happens first in code
  seems to be the case in KDE libs
Daniel
diff --git a/include/libxml/xmlerror.h b/include/libxml/xmlerror.h
index aa5078f..6a69512 100644
--- a/include/libxml/xmlerror.h
+++ b/include/libxml/xmlerror.h
@@ -1,8 +1,8 @@
+#include <libxml/parser.h>
+
 #ifndef __XML_ERROR_H__
 #define __XML_ERROR_H__
 
-#include <libxml/parser.h>
-
 #ifdef __cplusplus
 extern "C" {
 #endif