demos/scenario_hazard/job.ini:

Added missing parameters for the JB2009 ground motion correlation model.
job/validation:

Added `ground_motion_correlation_model` and `ground_motion_correlation_params`
to the list of params for the Scenario hazard calc.
demos/scenario_hazard/job.ini:

`vs30_clustering` is better set to `False`, according to Dr. Monelli.
Merge pull request #1028 from larsbutler/fix-scenario-hazard-correlation

Fixes scenario hazard correlation

[r=micheles] [f=*trivial]