Exit mc mirror when errors occur if retry is disabled and it's a watch operation

[jadolg]

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Description

When running mc mirror --watch the cli exits with a non-zero exit code instead of just printing the error.

Motivation and Context

I'm running mc mirror --watch in a systemd unit to constantly mirror my minio buckets to AWS S3. In the current state, it's not possible to monitor mc effectively since the process will just continue running.

How to test this PR?

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Optimization (provides speedup with no functional changes)
• 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)
• Unit tests added/updated
• Internal documentation updated
• Create a documentation update request here

[jadolg]

Solves #5162