dpkg setup failed during installation/upgrade due to spamd not able to setup IO::Socket::INET6 socket

[Darryl Baker]

Machine is configured without IPv6,

ProblemType: Package
DistroRelease: Ubuntu 14.04
Package: spamassassin 3.4.0-1ubuntu2.1
ProcVersionSignature: Ubuntu 3.13.0-49.83-generic 3.13.11-ckt17
Uname: Linux 3.13.0-49-generic i686
ApportVersion: 2.14.1-0ubuntu3.10
AptOrdering:
 spamassassin: Install
 spamassassin: Configure
Architecture: i386
Date: Sun May 3 06:20:56 2015
DpkgHistoryLog:
 Start-Date: 2015-05-03 06:19:35
 Commandline: apt-get --reinstall install spamassassin
 Reinstall: spamassassin:i386 (3.4.0-1ubuntu2.1)
DuplicateSignature: package:spamassassin:3.4.0-1ubuntu2.1:subprocess installed post-installation script returned error exit status 98
ErrorMessage: subprocess installed post-installation script returned error exit status 98
InstallationDate: Installed on 2013-06-28 (674 days ago)
InstallationMedia: Ubuntu-Server 12.04.2 LTS "Precise Pangolin" - Release i386 (20130214)
PackageArchitecture: all
SourcePackage: spamassassin
Title: package spamassassin 3.4.0-1ubuntu2.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 98
UpgradeStatus: Upgraded to trusty on 2014-04-22 (376 days ago)
mtime.conffile..etc.default.spamassassin: 2013-06-28T18:28:36.446290

Setting up spamassassin (3.4.0-1ubuntu2.1) ...
Starting SpamAssassin Mail Filter Daemon: server socket setup failed, retry 1: spamd: could not create IO::Socket::INET6 socket on [::1]:783: Cannot assign requested address
server socket setup failed, retry 2: spamd: could not create IO::Socket::INET6 socket on [127.0.0.1]:783: Address already in use
server socket setup failed, retry 3: spamd: could not create IO::Socket::INET6 socket on [127.0.0.1]:783: Address already in use
server socket setup failed, retry 4: spamd: could not create IO::Socket::INET6 socket on [127.0.0.1]:783: Address already in use
server socket setup failed, retry 5: spamd: could not create IO::Socket::INET6 socket on [127.0.0.1]:783: Address already in use
server socket setup failed, retry 6: spamd: could not create IO::Socket::INET6 socket on [127.0.0.1]:783: Address already in use
server socket setup failed, retry 7: spamd: could not create IO::Socket::INET6 socket on [127.0.0.1]:783: Address already in use
server socket setup failed, retry 8: spamd: could not create IO::Socket::INET6 socket on [127.0.0.1]:783: Address already in use
server socket setup failed, retry 9: spamd: could not create IO::Socket::INET6 socket on [127.0.0.1]:783: Address already in use
spamd: could not create IO::Socket::INET6 socket on [127.0.0.1]:783: Address already in use
invoke-rc.d: initscript spamassassin, action "start" failed.