gtk: Remove unused include statements which are not portable

These include files don't exist for MinGW and are not needed for Linux
(and hopefully for other hosts as well), so remove them.

Signed-off-by: Stefan Weil <sw@weilnetz.de>

ui/gtk.c

@@ -51,10 +51,6 @@
 #include <glib/gi18n.h>
 #include <locale.h>
 #include <vte/vte.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <sys/un.h>
-#include <sys/wait.h>
 #include <math.h>
 
 #include "ui/console.h"