__OpenBSD__ around pledge()

tmux.c

@@ -259,9 +259,11 @@ main(int argc, char **argv)
 	if (shell_cmd != NULL && argc != 0)
 		usage();
 
+#ifdef __OpenBSD__
 	if (pledge("stdio rpath wpath cpath flock fattr unix sendfd recvfd "
 	    "proc exec tty ps", NULL) != 0)
 		err(1, "pledge");
+#endif
 
 	if (!(flags & CLIENT_UTF8)) {
 		/*