MM-24759: fix order of calling SetstatusOnline (#14450)

We would call SetStatusOnline in a goroutine before actually calling HubRegister.
This could cause the message not to be sent after all, because there's no guarantee
that Register would actually happen before it.

To fix it, we just change the order of things.

Co-authored-by: mattermod <mattermod@users.noreply.github.com>

app/websocket_router.go

@@ -54,17 +54,17 @@ func (wr *WebSocketRouter) ServeWebSocket(conn *WebConn, r *model.WebSocketReque
 			return
 		}
 
-		wr.app.Srv().Go(func() {
-			wr.app.SetStatusOnline(session.UserId, false)
-			wr.app.UpdateLastActivityAtIfNeeded(*session)
-		})
-
 		conn.SetSession(session)
 		conn.SetSessionToken(session.Token)
 		conn.UserId = session.UserId
 
 		wr.app.HubRegister(conn)
 
+		wr.app.Srv().Go(func() {
+			wr.app.SetStatusOnline(session.UserId, false)
+			wr.app.UpdateLastActivityAtIfNeeded(*session)
+		})
+
 		resp := model.NewWebSocketResponse(model.STATUS_OK, r.Seq, nil)
 		hub := wr.app.GetHubForUserId(conn.UserId)
 		if hub == nil {