Install fails when using --skip-build
## Submitted by Michał Górny
**[Link to original bug (#16767)](https://bugzilla.xfce.org/show_bug.cgi?id=16767)**
## Description
To reproduce:
```
python setup.py build
python setup.py install --skip-build --root=/tmp/whatever
```
The error:
```
=== Installing catfish, version 1.4.13 ===
Root: /tmp/whatever
Prefix: /usr
Target Data: usr/
Target Scripts: /tmp/whatever/usr/bin/
Catfish Data Directory: /usr/share/catfish/
Desktop File: /tmp/whatever/usr/share/applications/org.xfce.Catfish.desktop
Moving icon file: /tmp/whatever/usr/share/catfish/media/catfish.svg -> /tmp/whatever/usr/share/icons/hicolor/scalable/apps/catfish.svg
Removing empty directory: /tmp/whatever/usr/share/catfish/media
ERROR: Can't find /tmp/whatever/usr/share/applications/org.xfce.Catfish.desktop
```
Version: 1.4.13
issue