always use a proper thread title at the main screen

app/src/main/kotlin/com/simplemobiletools/smsmessenger/adapters/MessagesAdapter.kt

@@ -108,7 +108,7 @@ class MessagesAdapter(
         view.apply {
             message_frame.isSelected = selectedKeys.contains(message.id)
 
-            message_address.text = message.participants.first().name
+            message_address.text = message.getThreadTitle()
             message_body_short.text = message.body
             message_date.text = message.date.formatDateOrTime(context, true)