Return wrong finishedTime without --wait flag when execute a function

[pzmrzy]

Bug Report

When execute a function without --wait, it return wrong finishedTime.

Expected behavior

Not return finishedTime field or the finishedTime is Unknown

Current behavior

The finished time is -62135596800

Steps to reproduce

1. Follow the quickstart guild
2. Run dispatch exec hello-py --input '{"name": "Jon", "place": "Winterfell"}'

Impact

• [x] Low - Annoyance, but does not impact business or functionality
• [ ] Medium - Issue can be worked around, but is causing pain
• [ ] High - Blocker