conversationmodel: show correct timestamp for syncing conversations

Because no interactions was added, a conversation was shown at the
bottom while syncing

Change-Id: I9cdba00f7fe328e0cf6486d7076fc377fc573a32

daemon @ c5bbd21e

-Subproject commit 977ee99c115f8435b0aa0521aa5b54ea7a2d4895
+Subproject commit c5bbd21e1c125f4012e2f88f485816a438ae62a7

src/libclient/conversationmodel.cpp

@@ -3256,6 +3256,16 @@ ConversationModelPimpl::addSwarmConversation(const QString& convId)
         }
     }
     if (details["syncing"] == "true") {
+        MapStringString messageMap = {
+            {"type", "initial"},
+            {"author", otherMember},
+            {"timestamp", details["created"]},
+            {"linearizedParent", ""},
+        };
+        auto msg = interaction::Info(messageMap, linked.owner.profileInfo.uri);
+
+        insertSwarmInteraction(convId, msg, conversation, true);
+        conversation.lastMessageUid = convId;
         conversation.needsSyncing = true;
         Q_EMIT linked.conversationUpdated(conversation.uid);
         Q_EMIT linked.dataChanged(indexOf(conversation.uid));