Fix hue retry crash

[balloob]

Description:

If Hue would need to retry connection, subsequent tries would crash because we were using hass.data[DOMAIN] for both config and bridge. Also, if unloading and setting up same host again, the YAML config would be lost.

Related issue (if applicable): fixes #

Pull request in home-assistant.io with documentation (if applicable): home-assistant/home-assistant.io#<home-assistant.io PR number goes here>

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