hydra: cannot change username, also update fullname

Dependencies

• [2] SZYDW2DG hydra: added some user admin
• [3] SMCOU72F hydra: add some admin for adding/enabling/etc build machines
• [*] ZWCTAZGL added newsitems, added some admin options to clear various caches.

Change contents

• replacement in src/lib/Hydra/Controller/Admin.pm at line 78
  [2.693]→[2.693:762](∅→∅)
  − { username => $username

  − , maxconcurrent => $fullname
  [2.693]

  [2.762]
  + { fullname => $fullname