package ntop 3:5.0.1+dfsg1-2.1ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[pawie]

unable to upgrade ntop on 15.04

ProblemType: Package
DistroRelease: Ubuntu 15.04
Package: ntop 3:5.0.1+dfsg1-2.1ubuntu1
ProcVersionSignature: Ubuntu 3.19.0-25.26-generic 3.19.8-ckt2
Uname: Linux 3.19.0-25-generic i686
ApportVersion: 2.17.2-0ubuntu1.2
Architecture: i386
Date: Thu Aug 13 10:05:22 2015
DuplicateSignature: package:ntop:3:5.0.1+dfsg1-2.1ubuntu1:subprocess installed post-installation script returned error exit status 1
ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationDate: Installed on 2015-06-08 (65 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release i386 (20150422)
RelatedPackageVersions:
 dpkg 1.17.25ubuntu1
 apt 1.0.9.7ubuntu4.1
SourcePackage: ntop
Title: package ntop 3:5.0.1+dfsg1-2.1ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.