Automatic merge from submit-queue

Remove all MAINTAINER statements in the codebase as they are deprecated

**What this PR does / why we need it**:
ref: https://github.com/docker/docker/pull/25466

**Release note**:

```release-note
Remove all MAINTAINER statements in Dockerfiles in the codebase as they are deprecated by docker
```
@ixdy @thockin (who else should be notified?)