[gxml] Fixed build by typo

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit 115928c74c804e69d618a1ed40b6d75536b3c5a8
Author: Daniel Espinosa <esodan gmail com>
Date:   Thu Jan 26 13:49:27 2017 -0600

    Fixed build by typo

 gxml/XParser.vala |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gxml/XParser.vala b/gxml/XParser.vala
index 1384faf..6354b2b 100644
--- a/gxml/XParser.vala
+++ b/gxml/XParser.vala
@@ -639,7 +639,7 @@ public class GXml.XParser : Object, GXml.Parser {
         if ("::" in pspec.get_nick ()) {
           attname = pspec.get_nick ().replace ("::","");
         } else {
-          warning (_("Invalid attribute name for Property: %s").printf (pspec.value_type));
+          warning (_("Invalid attribute name for Property: %s").printf (pspec.value_type.name ()));
           attname = pspec.get_nick ();
         }
       }