[gnome-builder] xml-pack: add missing GType definition

[Christian Hergert <chergert src gnome org>]

commit b6a35b62e79b3106bc012f6e08a6122f9aca0197
Author: Christian Hergert <chergert redhat com>
Date:   Fri Jun 15 18:17:07 2018 -0700

    xml-pack: add missing GType definition

 src/plugins/xml-pack/ide-xml-schema-cache-entry.h | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/plugins/xml-pack/ide-xml-schema-cache-entry.h 
b/src/plugins/xml-pack/ide-xml-schema-cache-entry.h
index 9ec477519..0ac74ca9c 100644
--- a/src/plugins/xml-pack/ide-xml-schema-cache-entry.h
+++ b/src/plugins/xml-pack/ide-xml-schema-cache-entry.h
@@ -62,6 +62,7 @@ struct _IdeXmlSchemaCacheEntry
   guint64            mtime;
 };
 
+GType                       ide_xml_schema_cache_entry_get_type      (void);
 IdeXmlSchemaCacheEntry     *ide_xml_schema_cache_entry_new           (void);
 IdeXmlSchemaCacheEntry     *ide_xml_schema_cache_entry_new_full      (GBytes                 *content,
                                                                       const gchar            *error_message);