Remove bol.com/kobo.com from shared list

[joost-vdpol]

https://github.com/apple/password-manager-resources/issues/580 introduced a shared backend quirk for bol.com and kobo.com. Bol.com and kobo.com are separate entities, kobo.com merely consumes bol.com's oAuth2 implementation. Login via bol.com lives on login.bol.com only, credentials will never have to be entered in kobo.com's separate backend. Users re-using the same password for bol.com and kobo.com are simply not adhering to password best practices.

Overall Checklist

• [x] I agree to the project's Developer Certificate of Origin
• [x] The top-level JSON objects are sorted alphabetically
• [x] There are no open pull requests for the same update

for shared-credentials.json

• [ ] There's evidence the domains are currently related (SSL certificates, DNS entries, valid links between sites, legal documents etc.)
• [ ] If using shared, the new group serves login pages on each of the included domains, and those login pages accept accounts from the others. (For example, we wouldn't use a shared association from google.co.il to google.com, because google.co.il redirects to accounts.google.com for sign in.)
• [ ] If using from and to, the new group, the from domain(s) redirect to the to domain to log in.

[calebd]

Thanks for the pull request! Could you please make the changes in quirks/shared-credentials.json instead of quirks/websites-with-shared-credential-backends.json? See Contributing a Shared Credentials entry for more information.