Fix a bug where config resources were always created in the Hub subscription

[glennmusa]

Description

Fixes a bug where deploy.sh will fail because it will always look in the hub subscription for the Terraform state storage account:

src/scripts/deploy.sh -s {config_sub_id} \
-u {hub_sub_id} \
-0 {t0_sub_id} \
-1 {t1_sub_id} \
-2 {t2_sub_id} \
-3 {t3_sub_id}

Would result in a Terraform initialization that specified the hub_sub_id as the place to search for Terraform state regardless of where it was actually deployed.

Issue reference

The issue this PR will close: #302

Checklist

Please make sure you've completed the relevant tasks for this PR, out of the following list:

• Code compiles or validates correctly
• BASH scripts have been validated using shellcheck
• All tests pass (manual and automated)
• The documentation is updated to cover any new or changed features
• Markdown files have been linted using the recommended linter. (See .vscode/extensions.json.)
• Relevant issues are linked to this PR