On windows "CodeChecker parse" command uses lowercase letter for disk

[dgiovanelli]

Hi, when used on Windows, the plugin uses lowercase letter for the disk name ("d:") when issuing commands on the terminal.

Most of the times this seems to be ok, however, the "CodeChecker parse" command, and in particular the "--file" argument seems to be case sensitive since with lowercase letter as disk name reports is empty, while with uppercase it contains data.