crash of user scripts in /etc/cron.[interval] cause apport-gtk to offer bug reporting

[Karl-Philipp Richter]

If a user script in `/etc/cron.[interval]` fails, e.g. a simple

    #!/usr/bin/python

    raise Error("Test")

in `/etc/cron.weekly/test.py`, `apport-gtk` offers to file a bug report which only makes sense if the script was installed by a system package of Ubuntu.

ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: apport-gtk 2.20.3-0ubuntu8
ProcVersionSignature: Ubuntu 4.8.0-28.30-generic 4.8.6
Uname: Linux 4.8.0-28-generic x86_64
NonfreeKernelModules: openafs zfs zunicode zcommon znvpair zavl
ApportVersion: 2.20.3-0ubuntu8
Architecture: amd64
CurrentDesktop: Unity
Date: Sun Dec 4 03:09:22 2016
InstallationDate: Installed on 2015-12-12 (357 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
PackageArchitecture: all
SourcePackage: apport
UpgradeStatus: Upgraded to yakkety on 2016-10-17 (47 days ago)