fix broken links on bitmask-oh-nine-four

There is a broken link, "handful of known issues", on
https://leap.se/en/about-us/news/2016/bitmask-oh-nine-four. This
ticket removes the link, as well as corrects 404 and 403 links.

* Documentation: #3
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Status Job ID Name Coverage
  Test
passed #26949
deploy

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