hydra-module: fix debug attribute

Dependencies

• [2] 2ANV36PB Hackery
• [3] ALLSLBFX Whoops
• [4] TTZ26BJQ Unify Hydra's NixOS module with the one used for hydra.nixos.org
• [5] D3MDJONY
• [6] BT6SNXUA Add an option to run the hydra server in debug mode
• [7] ZYEFL36Q Ported/merged properties from the TUD configuration's hydra-module
• [8] PMDWFZHW hydra-module.nix: Fix setting the logo

Change contents

• replacement in hydra-module.nix at line 33
  [3.35]→[3.0:62](∅→∅),[2.51]→[3.0:62](∅→∅),[3.205]→[3.0:62](∅→∅),[3.395]→[3.0:62](∅→∅)
  − } // (optionalAttrs cfg.debugServer { DBIC_TRACE = 1; });
  [2.51]

  [3.206]
  + } // (optionalAttrs cfg.debugServer { DBIC_TRACE = "1"; });