fix: prevent disabled job's next trigger date parse error

[sam80180]

If a job is disabled (by setting its cron expression to some time in the past), job list will have error showing this job.

Whether this PR is eventually merged or not, Sonic will thank you very much for your contribution.

无论此PR最终是否合并，Sonic组织都非常感谢您的贡献。

Checklist

• The title starts with fix, fea, or doc. | 标题为fix、feat或doc开头。
• I have checked that there are no duplicate pull requests with this request. | 我已检查没有与此请求重复的拉取请求。
• I have considered and confirmed that this submission is valuable to others. | 我已经考虑过，并确认这份呈件对其他人很有价值。
• I accept that this submission may not be used. | 我接受此提交可能不会被使用。

Description

[ZhouYixun]

LGTM！