pyhoca-gui leaves debug log outside rootdir in portable mode

It would be nice if the debug log file is stored inside the --sessions-rootdir so that files are kept within the "portable" definitions.

ATM, the log files is stored within User's home dir in temporary folder (e.g. AppData\Roaming\pyhoca-gui\PyHoca-GUI.1516.log).

Affected OS: Windows 7