[DISC] always auto-discover Presence/Tracker timeout (#1959)

auto-discover Presence/Tracker timeout even when HASS presence is not active

Also inject an additional placeholder rssi key and value into the BM2 voltage connection message to avoid the message being registered as a device tracker AWAY

https://community.openmqttgateway.com/t/bm2-home-and-away/3315

main/ZgatewayBT.ino

@@ -156,10 +156,6 @@ void BTConfig_fromJson(JsonObject& BTdata, bool startup = false) {
   if (startup == false) {
     if (BTdata.containsKey("hasspresence") && BTdata["hasspresence"] == false && BTConfig.presenceEnable == true) {
       BTdata["adaptivescan"] = true;
-#  ifdef ZmqttDiscovery
-      // Remove discovered entities
-      eraseTopic("number", (char*)getUniqueId("presenceawaytimer", "").c_str());
-#  endif
     } else if (BTdata.containsKey("hasspresence") && BTdata["hasspresence"] == true && BTConfig.presenceEnable == false) {
       BTdata["adaptivescan"] = false;
     }