Fix for bug #12409 (https://gna.org/bugs/index.php?12409).
This bug is the failure of the final stage of the 'full_analysis.py' script. If no models exist in the PDB file, a model number is no longer passed into add_struct().
Authored by: bugman 2008-10-05
Parent: [r7513]
Child: [r7515]
