[gtk+] Build Wayland backend by default

[Matthias Clasen <matthiasc src gnome org>]

commit 6671a5c9e4ee5ae5d6cedf32901dfdb1a3b741c9
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Aug 9 20:55:49 2013 -0400

    Build Wayland backend by default
    
    Unless an explicit backend is enabled via configure option, build
    both the X11 and Wayland backends.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=705498

 configure.ac |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 5992f0d..b0532d3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -314,6 +314,7 @@ if test -z "$backend_set"; then
     enable_win32_backend=yes
   else
     enable_x11_backend=yes
+    enable_wayland_backend=yes
   fi
 fi