Self hosted configuration uses plausible.io

[markatk]

If you enable self-hosted in the configuration the included script is still loaded from the main plausible.io site and thus doesn't work. Below is an example when a custom plausible instance is configured

<script src="https://plausible.io/js/plausible.js" async defer data-domain="example.com"></script>

Configuration:

enabled: true
active: true
data_domain: example.com
custom_event_goals: false
outbound_link_tracking: false
public_dashboard_visible: false
public_dashboard_url: null
self_hosting: true
custom_domain: https://plausible.example.com

[markatk]

I created a pull request #4 to fix the issue. Tested on my instance and resolves to the correct self hosted configuration.