[freeflow][documentation] Remove comment that outsideScvIdx is undefined if boundary is true. Reason: outsideScvIdx is properly filled in the else if of fvgridgeometry.hh. Additionally, it is called and used at the boundary.
[freeflow][documentation] Remove comment that outsideScvIdx is undefined if boundary is true. Reason: outsideScvIdx is properly filled in the else if of fvgridgeometry.hh. Additionally, it is called and used at the boundary.