remove rabbitmq plugin

[robkooper]

Description

docker instance of clowder will not start correctly. The docker image comes with rabbitmq plugin enabled that does not exist since 1.15.0. Unless this overriden (like it is done in the helm chart) this will prevent clowder from starting.

Review Time Estimate

• Immediately
• Within one week
• When possible

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My change requires a change to the documentation.
• I have updated the CHANGELOG.md.
• I have signed the CLA
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.