fix(deploy): quote EMAIL_FROM in /etc/gluecron.env

fix(deploy): quote EMAIL_FROM in /etc/gluecron.env

The deploy script was writing:
  EMAIL_FROM=gluecron <no-reply@gluecron.com>

When the script then source'd the env file, bash interpreted '<' as a
file-read redirect, throwing 'syntax error near unexpected token newline'
and aborting the deploy before migrations could run.

Quoting the value fixes it. Discovered when the new vultr-deploy.yml
workflow tried its first deploy and failed at exactly this line.