Fix openexchangerates form data description

[MartinHjelmare]

Breaking change

Proposed change

• Add missing description placeholder for the form data.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
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• Tests have been added to verify that the new code works.

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• Documentation added/updated for www.home-assistant.io

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  Updated by running python3 -m script.gen_requirements_all.
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[joostlek]

Shouldn't it be merged into dev?

[home-assistant]

Please take a look at the requested changes, and use the Ready for review button when you are done, thanks 👍

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[MartinHjelmare]

Yes, fixed. Thanks!