Fixed badge briefly visible when terminating conference

app/src/main/java/org/linphone/activities/voip/viewmodels/CallsViewModel.kt

@@ -314,6 +314,7 @@ class CallsViewModel : ViewModel() {
 
     private fun updateInactiveCallsCount() {
         // TODO: handle local conference
-        inactiveCallsCount.value = coreContext.core.callsNb - 1
+        val callsNb = coreContext.core.callsNb
+        inactiveCallsCount.value = if (callsNb > 0) callsNb - 1 else 0
     }
 }