Link won't save if scheme is missing

No error raised, simply ignores the entry.

Would suggest to allow entries without the scheme, default to http and handle the result.

An incorrect scheme will save but raises an error with metadata.

Start by reproducing the link-save behavior with a URL missing its scheme and with an incorrect scheme. Trace the desktop link-entry handling to determine why the missing-scheme entry is ignored; done means it is saved using an http default and incorrect schemes continue to report their metadata error.

Written by the indexing model from the issue text.