fix: wrap debug log when logger upated to using JSONLogFormatter

[brydoncheyney]

Messages logged by the __init() function by the json_logging logger are generally wrapped in ENABLE_JSON_LOGGING_DEBUG and ... - apart from one log event -

json-logging-python/json_logging/__init__.py

Line 130 in 0e520cc

_logger.debug("Update all existing logger to using JSONLogFormatter")

This is the only message being logged by a scheduled job we have running that uses json-logging-python. This should only be logged if explicitly enabled via ENABLE_JSON_LOGGING_DEBUG.