Support https

[andrefs]

I'm not familiar with HA code base. Would this be enough to allow support for HTTPS?

Configuration would be something like:

# Example configuration.yaml entry
sensor:
  - platform: netdata
    host: "192.168.1.2"
    scheme: "https"
    port: "19999"
    name: SomeHostName
    resources:
      system_load:
        data_group: system.load
        element: load15
      core0_freq:
        data_group: "cpu.cpufreq"
        element: "cpu0"
        icon: mdi:chip