Provide PaaS Docker nginx default vhosts

Summary:
Server cover page and domain not found

Ref T1595.

Test Plan:
Tested on Dwellers.

Unit tests provided for new node.get_ipv6_list function.

Reviewers: dereckson

Reviewed By: dereckson

Maniphest Tasks: T1595

Differential Revision: https://devcentral.nasqueron.org/D2227