Password check if 'backspace' is pressed when no character is buffered

[AlcideBava]

This issue is a....

[ ] Bug
[X] Other kind of issue (Please describe in detail)

Current Behavior

Let's say I made a typo while typing my password, I don't know where my mistake is exactly, I decide to erase everything.
When erasing while there is no character buffered, i3lock-color will check if password is correct. Since there is nothing it will of course be wrong but it is not counted as a failed attempt by option --show-failed-attempts.

Expected Behavior

Do not check for password correctness if I press 'Backspace' when there is no character buffered.

Reproduction Instructions

1. Lock
2. Press 'Backspace'

--ignore-empty-password option is set.

Environment

Output of i3lock --version:

i3lock version: 2.13.c.4-1

Where'd you get i3lock-color from?

[X] AUR package (which one?) => This one : https://aur.archlinux.org/packages/i3lock-color
[ ] Built from source yourself
[ ] Other (Please describe in detail)