Add missing header include in midi_channel_selector.h

diff --git a/gtk2_ardour/midi_channel_selector.h b/gtk2_ardour/midi_channel_selector.h
index f10c128b920aaae9a0760ecaa75e0b7917d38491..3ec2cfbd2cc0522c651078c010d4968f87e49310 100644 (file)
--- a/gtk2_ardour/midi_channel_selector.h
+++ b/gtk2_ardour/midi_channel_selector.h
@@ -25,6 +25,7 @@
 #include "sigc++/trackable.h"
 
 #include "gtkmm/table.h"
+#include "gtkmm/box.h"
 #include "gtkmm/button.h"
 #include "gtkmm/radiobutton.h"
 #include "gtkmm/label.h"