Fix DEB relationship field

[coleplx]

I faced an issue packaging ImageMagick for Ubuntu 20.04 where fpm complained about an invalid relationship field for a package.

According to https://www.debian.org/doc/debian-policy/ch-controlfields.html#version, I believe the field should support more characters.

The version number of a package. The format is: [epoch:]upstream_version[-debian_revision].
(...)
The upstream_version must contain only alphanumerics 6 and the characters . + - ~ (full stop, plus, hyphen, tilde) and should start with a digit. If there is no debian_revision then hyphens are not allowed.

Also, according to https://www.debian.org/doc/debian-policy/ch-relationships.html#syntax-of-relationship-fields,

All of the fields may restrict their applicability to particular versions of each named package. This is done in parentheses after each individual package name; the parentheses should contain a relation from the list below followed by a version number, in the format described in Version.