Back out part of 1.21, since it breaks script interactive-program. This

re-breaks non-interactive portupgrade (or at least old versions of
portupgrade); I'll see if I can put together a solution which avoids
breaking anything later.

Approved by:	rwatson (mentor)
Noticed by:	Stefan Farfeleder, Joshua Goodall

usr.bin/script/script.c

@@ -168,8 +168,7 @@ main(int argc, char *argv[])
 	FD_ZERO(&rfd);
 	for (;;) {
 		FD_SET(master, &rfd);
-		if (argv[0] == NULL)
-			FD_SET(STDIN_FILENO, &rfd);
+		FD_SET(STDIN_FILENO, &rfd);
 		if (flushtime > 0) {
 			tv.tv_sec = flushtime;
 			tv.tv_usec = 0;