MSAVI2 in Sessions/Session4/Part-1/Session4_1_HyperSpectral.ipynb is wrong

[guillepinto]

We have to modify that equation, otherwise the function below to implement that equation does not work. Related documentation:

• https://pypi.org/project/rindcalc/1.2.2/
• https://davinci.asu.edu/index.php?title=msavi2