[2.x] Logo in mail template resolves to flarum local disk by default

[luceos]

Current Behavior

The community logo attached to every email is retrieved using this code:

            @if ($settings->get('logo_path'))
                <img src="{{ $url->to('forum')->base() . '/assets/' . $settings->get('logo_path') }}" alt="{{ $settings->get('forum_title') }}" class="Header-logo">
            @else
                {{ $settings->get('forum_title') }}
            @endif

Reference: vendor/flarum/core/views/email/html.blade.php

As a consequence communities that use a bucket/cdn will always sent emails where the logo is broken.

Steps to Reproduce

.

Expected Behavior

The logo url should be based off of the disk config url value, not the base URL the UrlGenerator creates.

Screenshots

No response

Environment

• Flarum version: x.y.z
• Website URL: http://example.com
• Webserver: [e.g. apache, nginx]
• Hosting environment: [e.g. shared, vps]
• PHP version: x.y.z
• Browser: [e.g. chrome 67, safari 11]

Output of php flarum info

Output of "php flarum info", run this in terminal in your Flarum directory.

Possible Solution

No response

Additional Context

No response