bug: spellcheck underlines typos in urls

[SethFalco]

• [x] This is not a feature request (existing functionality does not work, not missing functionality). I will request features on forum or via support.
• [x] I've searched and did not find a similar issue.

Describe the bug The app spellchecks everything, including URLs.

To Reproduce Steps to reproduce the behavior:

1. Click "New email"
2. Type content in the message field, including a URL
3. See "https" and words in the URL get red underlines.

Expected behavior URLs (or any URI?) should be ignored from the spellcheck.

Screenshots

Desktop (please complete the following information):

• OS: Ubuntu 20.04.2 LTS x86_64
• Desktop Environment, if applicable (on Linux): GNOME
• Version [e.g. 22]: 3.84.4