[mutter] Only build Wayland protocols when we have Wayland

[Jasper St. Pierre <jstpierre src gnome org>]

commit 4c8a408afc746de0e8c87ace7b234b3371da72cc
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Wed Aug 27 12:05:51 2014 -0400

    Only build Wayland protocols when we have Wayland

 src/Makefile.am |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)
---
diff --git a/src/Makefile.am b/src/Makefile.am
index a6606ee..1e33608 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -36,11 +36,15 @@ mutter_built_sources = \
        $(dbus_display_config_built_sources)    \
        $(dbus_login1_built_sources)            \
        mutter-enum-types.h                     \
-       mutter-enum-types.c                     \
+       mutter-enum-types.c
+
+if HAVE_WAYLAND
+mutter_built_sources += \
        gtk-shell-protocol.c                    \
        gtk-shell-server-protocol.h             \
        xdg-shell-protocol.c                    \
        xdg-shell-server-protocol.h
+endif
 
 wayland_protocols = \
        wayland/protocol/gtk-shell.xml          \