Bug 1053940 - docker-worker: Encrypted environment variables

One open issue is the management of the gpg keys. Currently they are hard-coded.
Hmm... this is interesting. I suspect you're about to have a duh moment :)

Anyways, my recommendation remains that you don't check against `payload.created` for the following reasons:
 1. The property does exist (and shouldn't be defined)
 2. The proeprty you think of is `task.created` (but no need to check against it)
 3. Using encrypting env variables in template macros will be harder, if we do check against `task.created`.
     So only checking against `Date.now()` seems like a better solution.

**Note** the same arguments applies to the `encryptedData.deadline !==  payload.deadline` check below.
I think just deleting these lines will do...