Fix issues with messages processing

Signed-off-by: Mario Danic <mario@lovelyhq.com>

app/src/main/java/com/nextcloud/talk/controllers/ChatController.kt

@@ -1006,7 +1006,7 @@ class ChatController(args: Bundle) : BaseController(args), MessagesListAdapter
 
                 }
 
-                if (isFirstMessagesProcessing) {
+                if (wasFirstMessageProcessing && chatMessageList.size > 0) {
                     globalLastKnownFutureMessageId = chatMessageList[0].jsonMessageId
                 }