Update package maintainers in debian/control

Summary:
See title. I created a new mailing list specifically for package maintainers
so we can reuse this list for all package distribution.

Test Plan: Used a similar patch to upload https://launchpad.net/~jasonbcox/+archive/ubuntu/bitcoin-abc/+packages

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D5462