fix: copyObject encryption from unencrypted object

[harshavardhana]

Description

fix: copyObject encryption from unencrypted object

Motivation and Context

This is a continuation of #10085

How to test this PR?

Start MinIO server with this PR

~ export MINIO_KMS_MASTER_KEY=...
~ minio server --certs-dir ../minio-go/testcerts /tmp/fs{1...4}

Run functional test

~ make functional-test

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• Fixes a regression (If yes, please add commit-id or PR # here)
• Documentation needed
• Unit tests needed

[minio-trusted]

Mint Automation

Test	Result
mint-xl.sh	✔️
mint-large-bucket.sh	✔️
mint-fs.sh	✔️
mint-dist-xl.sh	✔️
mint-gateway-s3.sh	✔️
mint-gateway-azure.sh	✔️
mint-zoned.sh	✔️
mint-gateway-nas.sh	✔️
Deleting image on docker hub
Deleting image locally

[poornas]

LGTM