[17.0, 18.0] base_fontawesome_web_editor: Error when selecting a mass mailing template

[tarteo]

Module

base_fontawesome_web_editor

Describe the bug

When creating a mailing (Email marketing) an error popups after you select an template e.g. "Big News"

TypeError: Cannot read properties of null (reading '1')
    at http://oca-server-tools-17-0-bca78298eab0.runboat.odoo-community.org/web/assets/debug/web.assets_web.js:156208:73 (/web_editor/static/src/js/backend/convert_inline.js:843)
    at Array.find (<anonymous>)
    at http://oca-server-tools-17-0-bca78298eab0.runboat.odoo-community.org/web/assets/debug/web.assets_web.js:156205:59 (/web_editor/static/src/js/backend/convert_inline.js:840)
    at Array.find (<anonymous>)
    at fontToImg (http://oca-server-tools-17-0-bca78298eab0.runboat.odoo-community.org/web/assets/debug/web.assets_web.js:156204:25) (/web_editor/static/src/js/backend/convert_inline.js:839)
    at toInline (http://oca-server-tools-17-0-bca78298eab0.runboat.odoo-community.org/web/assets/debug/web.assets_web.js:156090:5) (/web_editor/static/src/js/backend/convert_inline.js:725)
    at http://oca-server-tools-17-0-bca78298eab0.runboat.odoo-community.org/web/assets/debug/web.assets_web.js:160631:19 (/mass_mailing/static/src/js/mass_mailing_html_field.js:150)
    at async MassMailingHtmlField._switchThemes (http://oca-server-tools-17-0-bca78298eab0.runboat.odoo-community.org/web/assets/debug/web.assets_web.js:161116:9) (/mass_mailing/static/src/js/mass_mailing_html_field.js:635)
    at async HTMLAnchorElement.<anonymous> (http://oca-server-tools-17-0-bca78298eab0.runboat.odoo-community.org/web/assets/debug/web.assets_web.js:160856:13) (/mass_mailing/static/src/js/mass_mailing_html_field.js:375)

To Reproduce

Affected versions:

17.0 and 18.0

Steps to reproduce the behavior:

1. Open Email Marketing > Mailings > New
2. Click a template e.g. "Big News"
3. the error pops up

Additional context
Tested on Runboat