Add WHOIS SSL response

[codec]

The 275 shows whether a client is connected using SSL.

[ghost]

Can you add tests for this, please?

[ward]

On freenode this reply seems to have numeric code 671, not 275.

Unhandled message: { prefix: 'wilhelm.freenode.net',
  server: 'wilhelm.freenode.net',
  command: '671',
  rawCommand: '671',
  commandType: 'normal',
  args: [ 'test-butler', 'ward', 'is using a secure connection' ] }

Is this even standardized somehow? I do not believe RFC 2812 specifies it.

After some googling: networks seem to have unofficially agreed upon 671. Only DALnet uses 275.

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On the topic of the actual change. If you set it to true if the reply is present, then I would think it reasonable to expect an ssl: false field to be there otherwise.