Fix hydra_logo setting

Dependencies

• [2] X5BWNTMA Make the logo configurable via hydra.conf
• [3] MVB7RRLT * Move NARs from the NixChannel controller to the Root controller and
• [4] AFEKITYD Fix some warnings about undefined values
• [5] IZEXRZWT Replace old logo with Nix/NixOS logo.
• [6] G4X5IUYJ Remove default logo, replaced by text for now. Hide template in jobset edit.
• [7] VH5ZABDR Add a page to show the latest evaluations for the entire server
• [8] 6KJXJB7N qualify ordery_by clauses when necessary, remove unnecessary order_by's, reported by Ludo, resulted in errors in sqlite
• [9] EFWN7JBV * Added a status page that shows all the currently executing build steps.
• [10] HRAFVVOE make logo configurable via HYDRA_LOGO env var
• [11] XJRJ4J7M Add user registration
• [*] J5UVLXOK * Start of a basic Catalyst web interface.

Change contents

• replacement in src/lib/Hydra/Controller/Root.pm at line 23
  [3.134]→[2.0:89](∅→∅)
  − $c->stash->{logo} = $c->config->{hydra_logo} // ($ENV{"HYDRA_LOGO"} ? "/logo" : "");
  [3.134]

  [3.40]
  + $c->stash->{logo} = ($c->config->{hydra_logo} // $ENV{"HYDRA_LOGO"}) ? "/logo" : "";
• replacement in src/lib/Hydra/Controller/Root.pm at line 277
  [3.323]→[3.323:382](∅→∅)
  − my $path = $ENV{"HYDRA_LOGO"} or die("Logo not set!");
  [3.323]

  [3.382]
  + my $path = $c->config->{hydra_logo} // $ENV{"HYDRA_LOGO"} // die("Logo not set!");