[Debian-med-packaging] Bug#1048443: Accepted igv 2.18.5+dfsg-2 (source) into unstable

[Santiago Vila]

Summary: The file test/data/prefs/testUserPrefs2.properties is
modified or not depending on the environment.

However, the produced .deb is the same regardless of the file being
present or being removed by debian/clean.

So the fix is to remove the file unconditionally (done in -4).

Thanks.