Fix some issues reported by lintian

Fix some issues reported by lintian

• Use secure URI in Homepage field. (homepage-field-uses-insecure-uri)
• Fix day-of-week for changelog entry 2.0.8. (debian-changelog-has-wrong-day-of-week)
• Set upstream metadata fields: Repository.

This merge proposal was created by the Janitor bot, and it will automatically rebase or close this proposal as appropriate when the target branch changes. Any comments you leave here will be read by the Janitor's maintainers.

Build and test logs for this branch can be found at https://janitor.debian.net/lintian-fixes/pkg/gftp/d287ca8a-57be-4d62-9c0a-b23579ab8cca.

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