Simplified handling of registering failed event

app/src/main/kotlin/com/tutpro/baresip/BaresipService.kt

@@ -428,7 +428,6 @@ class BaresipService: Service() {
                             status[account_index] = R.drawable.dot_white
                         else
                             status[account_index] = R.drawable.dot_green
-                        ua.registrationFailed = false
                         updateStatusNotification()
                         if (!Utils.isVisible())
                             return
@@ -439,10 +438,6 @@ class BaresipService: Service() {
                         if (ev.size > 1 && ev[1] == "Invalid argument")
                             // Likely due to DNS lookup failure
                             newEvent = "registering failed,DNS lookup failed"
-                        if (!ua.registrationFailed) {
-                            ua.registrationFailed = true
-                            updateNetwork()
-                        }
                         if (!Utils.isVisible())
                             return
                     }

app/src/main/kotlin/com/tutpro/baresip/UserAgent.kt

@@ -3,7 +3,6 @@ package com.tutpro.baresip
 class UserAgent(val uap: String) {
 
     val account = Account(Api.ua_account(uap))
-    var registrationFailed = false
 
     fun add(status: Int) {
         BaresipService.uas.add(this)