Add implicit default origin in case of port 80

[m-breitbach]

Please see the description in the PR:
#892

[cliffhall]

Closing: v1 is deprecated.

Thank you for reporting this, and apologies for the long wait for a response.

v1 will receive security fixes only — this issue describes a functionality, compatibility, or usability problem rather than a vulnerability, so it is being closed against v1. This is not a judgment on whether the problem is real — it's a consequence of the v1 line being frozen. This is happening as part of #1872.

If this still happens in v2, we'd genuinely like to know. v2 is a complete rewrite — three clients over a shared core — so many v1 behaviours no longer exist in the same form. Please open a fresh issue against v2 with steps to reproduce, and we'll look at it. Note that we accept external contributions as issues rather than pull requests; maintainers handle design and implementation through a prompt-driven workflow. See CONTRIBUTING.md.

Thanks for taking the time to report it.