[gxml] Fix typos in translatable strings added in the last commit

[Piotr Drąg <piotrdrag src gnome org>]

commit 76dc870a1eae3694fb61817ea7be55b78d7564a0
Author: Piotr Drąg <piotrdrag gmail com>
Date:   Thu Jan 18 22:27:06 2018 +0100

    Fix typos in translatable strings added in the last commit

 gxml/GomElement.vala |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/gxml/GomElement.vala b/gxml/GomElement.vala
index f01a6d6..3fd3f7a 100644
--- a/gxml/GomElement.vala
+++ b/gxml/GomElement.vala
@@ -444,7 +444,7 @@ public class GXml.GomElement : GomNode,
       unset (name);
       long i = index_of (name);
       if (i < 0) {
-        warning (_("No index found for ttribute %s").printf (name));
+        warning (_("No index found for attribute %s").printf (name));
       } else {
         order.unset (i);
       }
@@ -462,7 +462,7 @@ public class GXml.GomElement : GomNode,
       unset (k);
       long i = index_of (k);
       if (i < 0) {
-        warning (_("No index found for ttribute %s").printf (k));
+        warning (_("No index found for attribute %s").printf (k));
       } else {
         order.unset (i);
       }