Fixes in TP-Link Switch logging 0 values on init (#4026)

* Fixes in TP-Link Switch logging 0 values on init

On init of component the emeter would log to influxdb and possibly other inputs a 0 value, instead of not logging anything.
Initial polling should circumvent that behavior and avoid logging inconsistencies.

* Refactors update call in __init__

homeassistant/components/switch/tplink.py

@@ -37,7 +37,7 @@ def setup_platform(hass, config, add_devices, discovery_info=None):
     host = config.get(CONF_HOST)
     name = config.get(CONF_NAME)
 
-    add_devices([SmartPlugSwitch(SmartPlug(host), name)])
+    add_devices([SmartPlugSwitch(SmartPlug(host), name)], True)
 
 
 class SmartPlugSwitch(SwitchDevice):