Issue when loading a multimodel pdb file using discrete=1

[giagitom]

Hi, below is a minimal example of a pdb file presenting the issue. When I do load file.pdb, discrete=1 segmentation fault happens. Removing the empty model it works fine.

MODEL        1
ENDMDL
MODEL        2
ATOM      1  N   PRO A  89     -59.129 -26.013 -50.981  1.00  0.00          N
ATOM      2  CD  PRO A  89     -57.697 -26.031 -50.685  1.00  0.00          C
ENDMDL
END

[JarrettSJohnson]

Fixed by #261