url: exclude setting also applies to .title command

[dgw]

Description

Before Sopel 7.1, the only sane way to disable auto-title would have been setting the config option url.exclude to .* (matching any possible URL). The only problem is, doing that also makes .title not work.

At least as far back as Willie 4.0.0, when the responsible code was restructured (in d1acb12), and probably even longer, doing e.g. .title http://thisurlis.excluded would yield silence from the bot.

Recently, the silence has changed to an error message, since it's impossible for the code added in #1380 (then re-added in #2029) to tell the difference between a failed fetch, an excluded link, or a link handled by some other plugin.

Reproduction steps

1. Set url.exclude to .*
2. Run .title http://any.link/of/your/choosing
3. Get an error: "Sorry, fetching that title failed. Make sure the site is working."

Expected behavior

I expect Sopel to try and fetch the link's title anyway, because it's been explicitly requested.

Environment

• Sopel .version: 7.1.0-dev
• Sopel installed via: pip install -e
• Python version: 3.8.5
• Operating system: Ubuntu 18.04
• Relevant plugins: url

Notes

Since this behavior has been around for so long, I elected to hold any change until 8.0, even though any fix is probably trivial enough to include in 7.1 still. We'd be changing the meaning of a setting.

It seems easiest to fix both this and #2055 at the same time.