Cannot sync time zone for OmniPod if no pod is paired

[marionbarker]

Describe the bug This was discovered by @itsmojo with the recent change to daylight savings time.

To Reproduce Steps to reproduce the behavior:

1. If the phone has changed timezone but no pod is paired
2. An error is reported when you attempt to sync the pump time to the phone time.

Expected behavior Loop should update all the schedules to match phone time whether pod is paired or not.

See:

• https://github.com/LoopKit/OmniBLE/pull/115
• https://github.com/LoopKit/OmniKit/pull/29

Screenshots