* hydra: fix for dead link in context bar of build

Dependencies

• [2] QL55ECJ6 - adapted ui for hydra, more in line with nixos.org website

Change contents

• replacement in src/root/contextbar.tt at line 34
  [2.1123]→[2.1123:1227](∅→∅)
  − uri = c.uri_for(c.controller('Job').action_for('index'), [project.name, jobset.name, job.name])
  [2.1123]

  [2.1227]
  + uri = c.uri_for(c.controller('Job').action_for('overview'), [project.name, jobset.name, job.name])