[libgda] Require vala 0.15.1 to fix the build.

[Murray Cumming <murrayc src gnome org>]

commit 6335684bf8a179f7f36fe9a475fc5e968ec05b66
Author: Murray Cumming <murrayc murrayc com>
Date:   Thu Feb 2 10:58:14 2012 +0100

    Require vala 0.15.1 to fix the build.
    
    See bug #668765

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 0591538..0effa14 100644
--- a/configure.ac
+++ b/configure.ac
@@ -481,7 +481,7 @@ AC_ARG_ENABLE([vala-extensions],
 have_vala=no
 if test "x$found_introspection" = "xyes"
 then
-    VALA_MODULES="libvala-0.14 >= 0.14.0"
+    VALA_MODULES="libvala-0.16 >= 0.15.1".
     PKG_CHECK_MODULES(VALA, $VALA_MODULES,
     if test "$enable_vala" = "yes" -o "$enable_vala" = "auto"
 	then