Prediction and True Values Swapped in plot_forecast (utils.py)

[MMayr96]

https://github.com/timeseriesAI/tsai/blob/da5c10fa3480041c797a7e92b86f2c6876cbcf5c/tsai/utils.py#LL1635-L1638C80

Also, props to you. What an excellent repository!

[oguiza]

Thanks, @MMayr96!
Great catch! I'll fix it in a min.