Merge branch '145-linkNotFoundPage' into '2.2-dev'

Resolve "Display a "this link does not exist" page when navigating to a non existent Go link"

See merge request !95
4 jobs for 114-link-box-mobile-fix in 2 minutes and 10 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #2681
Go-py2.7

00:02:02

passed #2682
Go-py3.4

00:02:09

passed #2683
Go-py3.5

00:02:07

passed #2684
Go-py3.6

00:02:09