Clojure package remove source images

[gigasquid]

Description

The removes images from the clojure package to help resolve license issues from
#15542

Checklist

Essentials

Please feel free to remove inapplicable items for your PR.

• Changes are complete (i.e. I finished coding on this PR)
• All changes have test coverage:
• Unit tests are added for small changes to verify correctness (e.g. adding a new operator)
• Nightly tests are added for complicated/long-running ones (e.g. changing distributed kvstore)
• Build tests will be added for build configuration changes (e.g. adding a new build option with NCCL)
• Code is well-documented:
• For user-facing API changes, API doc string has been updated.
• For new C++ functions in header files, their functionalities and arguments are documented.
• For new examples, README.md is added to explain the what the example does, the source of the dataset, expected performance on test set and reference to the original paper if applicable
• Check the API doc at http://mxnet-ci-doc.s3-accelerate.dualstack.amazonaws.com/PR-$PR_ID/$BUILD_ID/index.html
• To the my best knowledge, examples are either not affected by this change, or have been fixed to be compatible with this change

[roywei]

LGTM, thanks for the fix!

[kedarbellare]

LGTM thanks!

[TaoLv]

Thank you @gigasquid for the contribution. Would you mind picking this to the v1.5.x branch? We hope the license issue can be addressed in the 1.5.x patch release. Thanks!

[gigasquid]

@TaoLv - I meant to do a PR to the v1.5.x branch for the cherry-pick, but instead I pushed the commit to the branch directly https://github.com/apache/incubator-mxnet/commits/v1.5.x

I think it's fine, but if you want to double check, that would be great.