[seahorse] Add missing build dep

[Kalev Lember]

commit c4b7487595cde92f9cc917f404cb5ff381cd7ad0
Author: Kalev Lember <kalevlember at gmail.com>
Date:   Thu May 15 21:49:02 2014 +0200

    Add missing build dep

 seahorse.spec |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/seahorse.spec b/seahorse.spec
index 734c603..0308f8c 100644
--- a/seahorse.spec
+++ b/seahorse.spec
@@ -32,6 +32,8 @@ BuildRequires:  libSM-devel
 BuildRequires:  GConf2-devel
 # for g-ir-scanner
 BuildRequires:  libtool
+BuildRequires:  vala
+
 Requires(post): desktop-file-utils
 Requires(post): /usr/bin/gtk-update-icon-cache
 Requires(postun): desktop-file-utils