Umstellung auf UTC Timestamp

lib/content_views/messages_page.dart

@@ -93,7 +93,7 @@ class _MessagesPageState extends State<MessagesPage> with ProducerMixin {
     message.text = text.text;
     message.from = _sid;
     message.subj = '';
-    message.time = Util.toUnixMillisUtc(now.toUtc());
+    message.time = Util.nowUnixSecondsUtc();
     message.read = true;
     message.id = await sbmessage.ChatMessage.getNextId();
 
@@ -214,7 +214,7 @@ class _MessagesPageState extends State<MessagesPage> with ProducerMixin {
 
       var chatMessagesShowed = ChatMessagesReceived();
       chatMessagesShowed.ids = chatMessageIds;
-      chatMessagesShowed.time = Util.toUnixMillisUtc(DateTime.now().toUtc());
+      chatMessagesShowed.time = Util.nowUnixSecondsUtc();
 
       sendMessage(
         routingKey: Constants.messageTopicPublishPayload,