[msitools] wixl: do not add null/runtime properties

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

commit 696c5f4335264dedbdf612ddf73b38d664bc1684
Author: Marc-Andrà Lureau <marcandre lureau gmail com>
Date:   Thu Jan 24 23:43:05 2013 +0100

    wixl: do not add null/runtime properties

 tools/wixl/builder.vala |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/tools/wixl/builder.vala b/tools/wixl/builder.vala
index fc511d9..c89093f 100644
--- a/tools/wixl/builder.vala
+++ b/tools/wixl/builder.vala
@@ -280,6 +280,9 @@ namespace Wixl {
         }
 
         public override void visit_property (WixProperty prop) throws GLib.Error {
+            if (prop.Value == null)
+                return;
+
             db.table_property.add (prop.Id, prop.Value);
         }