[gnome-code-assistance] build: add Vala 0.28

[Sébastien Wilmet <swilmet src gnome org>]

commit 126b5781748ce9bf5d822a2b9692adf6cd9f6487
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Mon Dec 29 18:43:25 2014 +0100

    build: add Vala 0.28

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 573fbcc..224e74b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -395,7 +395,7 @@ AC_ARG_ENABLE([vala],
               [enable_vala=$enableval],
               [enable_vala=auto])
 
-BACKEND_VALA_LIBVALA_VERSIONS="libvala-0.26 libvala-0.24 libvala-0.22 libvala-0.20"
+BACKEND_VALA_LIBVALA_VERSIONS="libvala-0.28 libvala-0.26 libvala-0.24 libvala-0.22 libvala-0.20"
 BACKEND_VALA_MODULES="gobject-2.0 >= 2.36 glib-2.0 >= 2.36 gio-2.0 >= 2.36 gee-0.8 gio-unix-2.0 >= 2.36"
 
 BACKEND_VALA_LIBVALA=