This change accompanies the `--no-cd` option when configured via
resources. It is required to support `Git Bash Here`: when
right-clicking an icon in the Explorer to start a Bash, the working
directory is actually the directory that is displayed in the Explorer.
That means if the clicked icon actually refers to a directory, the
working directory would be its *parent* directory.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>