BUG: fix filtering of diagonals in `rlgl.calculateRLGL`
BUG: fix filtering of diagonals in `rlgl.calculateRLGL`

For each angle, the found diagonals are filtered, where the goal is to filter out diagonals containing only the `padVal`.
However, currently, also diagonals containing one and only one voxel with a non-padVal value are excluded.
(in this case, the size of the array returned by numpy.nonzero is 1).

Change  `numpy.nonzero(x != padValue)[0].size > 1` to  `numpy.nonzero(x != padValue)[0].size > 0`,
so the filter also includes the diagonals where there is one voxel with a non-padVal value and
only excludes diagonals containing only padVal values.

Radiomics/pyradiomics,Radiomics/pyradiomics,Radiomics/pyradiomics,Radiomics/pyradiomics