Re-inserted safety checks in lin/dispersion/cr72.py file.
This is re-inserted for the rank_1 cases.
This makes the unit-tests pass again.
Task #7807 (https://gna.org/task/index.php?7807): Speed-up of dispersion models for Clustered analysis.
Authored by: tlinnet 2014-06-08
Parent: [r23731]
Child: [r23733]
