fix: continue_next should be true by default

[medcl]

This pull request includes several changes to the loader.go file to improve logging, error handling, and debugging capabilities. The most important changes include fixing a typo in an error message, adding additional logging for assertion failures, modifying the return values of a function, and enhancing debug logging.

Improvements to logging and error handling:

• Fixed a typo in the error message from "whilte" to "while" in the doRequest function.
• Added an informational log message when an assertion fails and subsequent requests are skipped.

Enhancements to function return values and debugging:

• Changed the return values of the doRequest function to return a boolean and an error instead of just returning.
• Added the index variable i to the loop over config.Requests in the Run function to facilitate better logging.
• Enhanced debug logging in the Run function to include the request index, continuation status, and error details.

[luohoufu]

LGTM