Fix 'TODO: section 2.4.2.3 constrains the email address to a limited subset of valid address formats' issue in sifter\commands\redirect.py

[manfred-kaiser]

section 2.4.2.3 constrains the email address to a limited subset of valid address formats. need to check if python's email.utils also uses this subset or if we need to do our own parsing

CodeFactor found an issue: TODO: section 2.4.2.3 constrains the email address to a limited

It's currently on:
sifter\commands\redirect.py:40
Commit 6e6601e