[gnome-themes-standard] Add Adwaita-dark Makefile's to AC_CONFIG_FILES

[Owen Taylor <otaylor src gnome org>]

commit c021ce92f939565e6c47184a3649cf725f52adbb
Author: Owen W. Taylor <otaylor fishsoup net>
Date:   Tue Oct 4 22:50:26 2016 -0400

    Add Adwaita-dark Makefile's to AC_CONFIG_FILES
    
    This was missed in the recent merge of Adwaita-dark changes.
    These were missed in

 configure.ac |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 8098e14..ad1e5d1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -85,6 +85,9 @@ themes/Makefile
 themes/Adwaita/Makefile
 themes/Adwaita/gtk-2.0/Makefile
 themes/Adwaita/gtk-3.0/Makefile
+themes/Adwaita-dark/Makefile
+themes/Adwaita-dark/gtk-2.0/Makefile
+themes/Adwaita-dark/gtk-3.0/Makefile
 themes/HighContrast/Makefile
 themes/HighContrast/gtk-2.0/Makefile
 themes/HighContrast/gtk-3.0/Makefile