can't set logging directory correctly

version: 2.6.0 prerelease 2

Summary:

I want to automatically save the log file to a seperate directory every time I start a session. but the log files always located at default log path even if i specified absolute path.

Repro steps:
1. open session setting window,
2. click the browse button and set the file path, like : `D:\workspace\windterm\%n_%Y-%m-%d_%H-%M-%S.log`.
3. excute some command or restart the session.
4. open the logging directory (`D:\workspace\windterm\`) , you will find out it's empty
5. now checkout the default logging path, you will find log files at `.wind\profiles\default.v10\terminal\logs\{session name}\D%3A\workspace\windterm`

Start in the session setting window and reproduce the logging path using the absolute Windows path from the report. Compare the selected path with the default log location and verify that a new session writes logs to the requested directory rather than creating the reported encoded path.

Written by the indexing model from the issue text.