password is shown as plain text at sync-diff-inspector

[Takashi-kun]

Feature Request

Is your feature request related to a problem? Please describe: Not related to a problem

Describe the feature you'd like: sync-diff-inspector log shows data source password as plain text, I want them to be masked because they are sensitive value for us

Describe alternatives you've considered:

• copy values and replace with masking here > https://github.com/pingcap/tidb-tools/blob/master/sync_diff_inspector/main.go#L101

Teachability, Documentation, Adoption, Migration Strategy: