[msitools] Fix stable component GUID generation

[Marc-Andre Lureau <malureau src gnome org>]

commit fe1d1021499b3325a90dfe32b6c4bbbc6de7fd08
Author: Marc-André Lureau <marcandre lureau gmail com>
Date:   Fri Nov 8 15:07:48 2013 +0100

    Fix stable component GUID generation
    
    Paolo probably overlooked the difference between WixlElement.parent, and
    Vala 'base'

 tools/wixl/wix.vala |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/tools/wixl/wix.vala b/tools/wixl/wix.vala
index 6566920..5e290fb 100644
--- a/tools/wixl/wix.vala
+++ b/tools/wixl/wix.vala
@@ -1072,7 +1072,7 @@ namespace Wixl {
             if (key == null)
                 throw new Wixl.Error.FAILED("a child is needed to generate a component GUID");
 
-            return parent.full_path (r) + "/" + key.path_name ();
+            return base.full_path (r) + "/" + key.path_name ();
         }
 
     }