lineedit: fix another corner case with bad unicode input

function                                             old     new   delta
read_key                                             607     646     +39
readit                                                50      55      +5
getch_nowait                                         290     295      +5
hash_find                                            233     234      +1
xstrtoul_range_sfx                                   231     230      -1
passwd_main                                         1058    1056      -2
builtin_exit                                          45      43      -2
cmp_main                                             649     645      -4
lineedit_read_key                                    257     245     -12
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/5 up/down: 50/-21)             Total: 29 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/editors/vi.c b/editors/vi.c
index c4bca2a..a22a6a1 100644
--- a/editors/vi.c
+++ b/editors/vi.c
@@ -2205,7 +2205,7 @@
 	int c;
 
 	fflush_all();
-	c = read_key(STDIN_FILENO, readbuffer);
+	c = read_key(STDIN_FILENO, readbuffer, /*timeout off:*/ -2);
 	if (c == -1) { // EOF/error
 		go_bottom_and_clear_to_eol();
 		cookmode(); // terminal to "cooked"