"Enter choice" message disappears

[rvalitov]

Hi!
After update to latest MTProxyMax and checking for the update again, the message "Enter choice" disappears:

[SamNet-dev]

Fixed in 5d2274e.

The input drain (added in #38 to fix double-input) used read -s (silent mode) which disables terminal echo. On Alpine, bash may not restore echo mode after a read timeout, causing the "Enter choice" prompt to become invisible.

Fix: dropped the -s flag — silent mode isn't needed for draining stale input bytes.

mtproxymax update to pick this up.

[rvalitov]

@SamNet-dev I have updated, still see this issue: