GTC-1866: fix: Remove extra quotes from error message

[gtempus]

I didn't notice the subtle difference between the variables: https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-mapping-template-reference.html

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• Make sure you are requesting to pull a topic/feature/bugfix branch (right side). Don't request your master!
• Make sure you are making a pull request against the develop branch (left side). Also you should start your branch off our develop.
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Pull request type

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• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

The error message for an integration timeout has a double set of quotation marks. It's not valid JSON:
Request: https://data-api.globalforestwatch.org/assets
Response:

{
    "status": "failed",
    "message": " "Endpoint request timed out" : Use the pagination query parameters when available. See the API documentation."
}

Issue Number: GTC-1866

What is the new behavior?

The new property should not have quotation marks.

Does this introduce a breaking change?

• Yes
• No

Other information