fixed crash when deleting an account

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

@@ -217,7 +217,7 @@ class BaresipService: Service() {
         if (!IS_SERVICE_RUNNING) return
         val ua = UserAgent.find(MainActivity.uas, uap)
         if (ua == null) {
-            Log.e(LOG_TAG, "updateStatus did not find ua $uap")
+            Log.w(LOG_TAG, "updateStatus did not find ua $uap")
             return
         }
         val aor = ua.account.aor

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

@@ -314,7 +314,11 @@ class MainActivity : AppCompatActivity() {
     }
 
     private fun handleServiceEvent(event: String, uap: String, callp: String) {
-        val ua = UserAgent.find(uas, uap)!!
+        val ua = UserAgent.find(uas, uap)
+        if (ua == null) {
+            Log.w("Baresip", "handleServiceEvent '$event' did not find ua $uap")
+            return
+        }
         val aor = ua.account.aor
         val acc = ua.account
         val ev = event.split(",")