fix(nextcloud): truly not require SSE-C

[jstewart612]

Description of the change

Make SSE-C truly not be required just as the upstream project does not require SSE-C.

Benefits

Make SSE-C truly not be required just as the upstream project does not require SSE-C.

Possible drawbacks

None: only makes Helm chart more compliant with available upstream options.

Applicable issues

• fixes part of #612

Additional information

Checklist

• [x] I have read the CONTRIBUTING.md doc.
• [x] DCO has been signed off on the commit.
• [x] Chart version bumped in Chart.yaml according to semver.
• [x] (optional) Parameters are documented in the README.md