Artifact download failed from S3 after build deleted

Summary

When a build has been deleted, artifact download task in deployment plan won't be able to use the artifact anymore if S3 artifact handler is configured for plan.

Steps to Reproduce

1. Create a build plan with artifact definition and run it
2. Create a deployment plan with 2 identical envs and use artifact download task to get the artifact from the above build plan
3. Run the first environment
4. Delete the build result used for version
5. Run the second environment with same version

Expected Results

The artifact can still be used even the build result has been deleted.

Actual Results

The task will fail with:

simple 28-Jul-2016 12:23:36 Preparing to download plan result DELETED_ABC-DFGPLAN27-5 artifact: Shared artifact: [ABC WAR], pattern: [**/*.war]
error 28-Jul-2016 12:23:36 Required storage tag not found in context
error 28-Jul-2016 12:23:36 Unable to download artifact Shared artifact: [ABC WAR], pattern: [**/*.war]