Fix Custom Sensitive Variable fields feature

[kaxil]

#9397 added this feature but broke Master

---

Make sure to mark the boxes below before creating PR: [x]

• Description above provides context of the change
• Unit tests coverage for changes (not needed for documentation changes)
• Target Github ISSUE in description if exists
• Commits follow "How to write a good git commit message"
• Relevant documentation is updated including usage instructions.
• I will engage committers as explained in Contribution Workflow Example.

---

In case of fundamental code change, Airflow Improvement Proposal (AIP) is needed.
In case of a new dependency, check compliance with the ASF 3rd Party License Policy.
In case of backwards incompatible changes please leave a note in UPDATING.md.
Read the Pull Request Guidelines for more information.

[ashb]

Tests still not 100% happy though

[kaxil]

Tests still not 100% happy though

-----------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------
             Checking integration openldap
-----------------------------------------------------------------------------------------------

             Integration openldap OK!

-----------------------------------------------------------------------------------------------

Error: some of the CI environment failed to initialize!

###########################################################################################
                   EXITING /opt/airflow/scripts/ci/in_container/check_environment.sh WITH STATUS CODE 254
###########################################################################################

Error: check_environment returned 254. Exiting.

###########################################################################################
                   EXITING /entrypoint WITH STATUS CODE 254
###########################################################################################
###########################################################################################
                   EXITING WITH STATUS CODE 254
###########################################################################################

Finished the script ci_run_airflow_testing.sh
Elapsed time spent in the script: 139 seconds
Exit code 254

Environment related issue in one of the tests

[potiuk]

still test_can_handle_error_on_decrypt fails consistently :(

[kaxil]

still test_can_handle_error_on_decrypt fails consistently :(

Yup, fixing it too