Hi there,
There is nothing to be worried about, it’s success indication which plugin sends to debug log using standard PHP error_log facility. In that way WordPress plugins can not control the underlying presence or absence of debug logging information. In order to turn off debug logging WP_DEBUG_LOG should be set to false (more info: https://codex.wordpress.org/Debugging_in_WordPress#WP_DEBUG_LOG). It’s also recommended to turn general WordPress debugging off by setting WP_DEBUG to false on production installations.
Best – O/S Team
