apc mode/Propagate "mode" between frontend and /api/default route

[suddencoffee]

Right now /api/default does not work for "apc" mode as it defaults to the "nut" mode, even if the config specifies mode='apc'

Here is my config fragment:

servers:
  - server: "192.168.7.125"
    port: 3551
    default: true
    mode: 'apc'
    devices:
      - device: 'nix'
        mode: 'apc'
        power: 900
        displayname: 'Back-UPS RS 1500MS2'