client: Fix prompt masking

Entering 23 characters at a prompt resulted in 9 extra characters being
added to the line. At this point, you would only be abel to backspace
until the 9th character.

It seems that claling both rl_replace_line("", 0) and rl_redisplay()
before rl_replace_line(masked_input.mask, 0) causes this to happen. Both
calls are redundant anyways as iwctl functions exactly the same without
them (plus no more bug).
1 file changed