Only listen for zeroconf when the esphome device cannot connect

[bdraco]

Proposed change

Followup to #48129

I installed beta on a system with ~108 esphome devices and found the executor got overloaded at startup with 2021-04-03 02:47:34 DEBUG (MainThread) [homeassistant.runner] Calling executor with function: <bound method Zeroconf.add_listener of <homeassistant.components.zeroconf.models.HaZeroconf object at 0x7f86f6bae400>>, args: (<homeassistant.components.esphome.ReconnectLogic object at 0x7f86ef8e1460>, None), kwargs: {}

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