Task with cron runs an hour later the first time

__Steps to reproduce:__
List the minimal actions needed to reproduce the behavior.

1. Create task with cron at 15:00 (system time) -> for example: option task = {name: "CalculosT1", cron: "0 15 * * *", offset: 15m}

__Expected behavior:__
This task should be executed EVERY TIME at 15:00 (system time), in my case 14:00 UTC

__Actual behavior:__
First time after save or after reload docker container, the task runs 1 hour after, at 16 (system time)/ 15:00 UTC, it seems like dont get the cron correctly. Then, the other times it runs at 15:00 (system time)

__Environment info:__

* System info: Linux 4.19.104-microsoft-standard x86_64
* InfluxDB version: InfluxDB 2.0.3 (git: fe04d346df) build_date: 2020-12-15T01:00:16Z
* Other relevant environment details: Docker version 3.0.0 (50684)

__Config:__

__Logs:__

__Performance:__

No source file, test, or entry point is named. Reproduce the task using cron "0 15 * * *" with a 15-minute offset in InfluxDB 2.0.3, including after saving and reloading the Docker container, then verify that the first and subsequent executions occur at the expected system time.

Written by the indexing model from the issue text.