Bug#977643: equivs: Can't specify spoofed package version

[5990]

Woops, I forgot to answer a couple questions :p

> Kali should have much newer version of equivs than 2.2.0. It should
have 2.3.1.

I don't know what to tell you, I did an `apt update` before installing `equivs`
This are the contents of my `/etc/apt/sources.list`:
```
# Debian packages for stable
deb http://debian.unnoba.edu.ar/debian/ stable main contrib
# Uncomment the deb-src line if you want 'apt-get source'
# to work with most packages.
# deb-src http://debian.unnoba.edu.ar/debian/ stable main contrib

# Security updates for stable
deb http://security.debian.org/ stable/updates main contrib
```

> [..] But maybe that was just a mail client or editor issue.
Yeah, I think so too. Somewhere along the way, the trailing space must've been removed.