hydra-module.nix: Make services require hydra-init

Dependencies

• [2] ZYEFL36Q Ported/merged properties from the TUD configuration's hydra-module
• [3] D3MDJONY
• [4] J57PR4O3 hydra-module: Allow to specify the listen host.
• [5] 25DXUDOJ hydra-module.nix: Remove the useWAL option
• [6] L62I7CPI Don't put ssmtp in hydra's paths
• [7] 7XOH2DGH hydra-module.nix: Give types to options
• [8] KMPLMG7T hydra-module.nix: Cleanup
• [9] BT6SNXUA Add an option to run the hydra server in debug mode

Change contents

• replacement in hydra-module.nix at line 198
  [2.1045]→[2.1045:1087](∅→∅)
  − wants = [ "hydra-init.service" ];
  [2.1045]

  [2.1087]
  + requires = [ "hydra-init.service" ];
• replacement in hydra-module.nix at line 210
  [2.1487]→[2.1487:1529](∅→∅)
  − wants = [ "hydra-init.service" ];
  [2.1487]

  [2.1529]
  + requires = [ "hydra-init.service" ];
• replacement in hydra-module.nix at line 224
  [2.2002]→[2.2002:2044](∅→∅)
  − wants = [ "hydra-init.service" ];
  [2.2002]

  [2.2044]
  + requires = [ "hydra-init.service" ];
• replacement in hydra-module.nix at line 236
  [2.2398]→[2.2398:2440](∅→∅)
  − { wants = [ "hydra-init.service" ];
  [2.2398]

  [2.2440]
  + { requires = [ "hydra-init.service" ];