Simplify IPv6 support

We do not need to customize the config template for IPv6. We could remove these changes (2 blocks referencing CIPAAS-141) and instead set in the router environment:

ROUTER_SERVICE_HTTP_PORT=80,:::80
ROUTER_SERVICE_HTTPS_PORT=443,:::443

These values should work even with the current customizations.

NB: we need to remove use of ROUTER_SERVICE_HTTP_PORT in peer definition. Instead compare endpoint port with 1936 (the peer sync port)