Only delete stack user project from correct domain

Check the domain ID for the project matches the configured domain from
heat.conf, so we avoid the bad outcome of deleting the user's project
when heat has been configured for stack domain users after creating
some stacks.

Change-Id: I247e732033f44daf0de5b0efeff6c263814d13ab
Closes-Bug: #1365332
Merge "Only delete stack user project from correct domain"