Fix empty parameter_default error in environment file
Fix empty parameter_default error in environment file

Providing an empty 'parameter_defaults' is resulting in overriding
of all the previously populated 'parameters_defaults' as None.
Commenting the empty statement and cleaned-up emtpy line in j2
templating.

Change-Id: I75bac6b558ac16a08e0964599cecae5bf10edf8a

openstack/tripleo-heat-templates,openstack/tripleo-heat-templates,dprince/tripleo-heat-templates,dprince/tripleo-heat-templates