Update run.ts

[liushmh]

if save to db failed, finished should stay false, otherwise, the job could never be completed.

[liushmh]

Be more specific:
if save is failed, the status of 'old' job is 'finished', but field 'lastFinishedAt' is not updated into database,
so is-running.ts will always return true.
In this case, the real 'new' job will never start.

[harisvsulaiman]

@liushmh Please write a test case for the problem you are trying to solve