Fix debug log message so that it does not contain null characters. This bug was the cause that debug log file was recognized to be binary file.
Fix debug log message so that it does not contain null characters.
This bug was the cause that debug log file was recognized to be binary file.

treasure-data/prestogres,treasure-data/prestogres,treasure-data/prestogres,treasure-data/prestogres,treasure-data/prestogres,treasure-data/prestogres,treasure-data/prestogres