dpkg installation routine of dlm depends on corosync to be installed and started

[Karl-Philipp Richter]

`sudo apt-get install dlm` fails with

    dlm (4.0.1-0ubuntu2) wird eingerichtet ...
    insserv: warning: script 'K01irda-setup' missing LSB tags and overrides
    insserv: Service corosync has to be enabled to start service dlm_controld
    insserv: exiting now!
    update-rc.d: error: insserv rejected the script header
    dpkg: Fehler beim Bearbeiten des Paketes dlm (--configure):
     Unterprozess installiertes post-installation-Skript gab den Fehlerwert 1 zurück

and only succeeds if `corosync` is installed and the service enabled with `sudo systemd enable corosync`.

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: dlm 4.0.1-0ubuntu2
ProcVersionSignature: Ubuntu 4.2.0-32.37-generic 4.2.8-ckt4
Uname: Linux 4.2.0-32-generic x86_64
ApportVersion: 2.19.1-0ubuntu5
Architecture: amd64
CurrentDesktop: Unity
Date: Mon Feb 29 22:02:45 2016
InstallationDate: Installed on 2013-10-17 (865 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release amd64 (20130424)
SourcePackage: dlm
UpgradeStatus: Upgraded to wily on 2015-11-19 (102 days ago)