Improve error log message when no sns->sqs context found.

[purple4reina]

What does this PR do?

Instead of logging

Datadog Lambda Python only supports extracting trace context from String or Binary SQS/SNS message attributes

The tracer extractor returned with error local variable 'dd_json_data' referenced before assignment

log

The tracer extractor returned with error Datadog Lambda Python only supports extracting trace context from String or Binary SQS/SNS message attributes

Motivation

Testing Guidelines

Additional Notes

Types of Changes

• Bug fix
• New feature
• Breaking change
• Misc (docs, refactoring, dependency upgrade, etc.)

Check all that apply

• This PR's description is comprehensive
• This PR contains breaking changes that are documented in the description
• This PR introduces new APIs or parameters that are documented and unlikely to change in the foreseeable future
• This PR impacts documentation, and it has been updated (or a ticket has been logged)
• This PR's changes are covered by the automated tests
• This PR collects user input/sensitive content into Datadog
• This PR passes the integration tests (ask a Datadog member to run the tests)

[astuyve]

looks okay here, not sure how heavy throwing an exception is (kind of cpu intensive in node), but the logic is sound