Correct the spelling for the word constraint
Correct the spelling for the word constraint

In some places, the word constraint is not spelled
correctly. This patch fixes it.

Change-Id: I2e581995ed28624d39f59c3cfdda86c4815c4d5f

dims/heat,dragorosson/heat,noironetworks/heat,dims/heat,noironetworks/heat,cwolferh/heat-scratch,steveb/heat,jasondunsmore/heat,openstack/heat,jasondunsmore/heat,openstack/heat,steveb/heat,gonzolino/heat,gonzolino/heat,cwolferh/heat-scratch,dragorosson/heat