Bug#825919: debian-edu-config: shouldn't purge libnss-mdns which is needed by cups for printer detection
In src:debian-edu 1.812+deb8u1 the package libnss-mdns has been added to the
tasks main-server and desktop-other (binaries education-main-server and
education-desktop-other to fix automatic printer detection (which is vital
for Debian Edu users). This package is needed cause cups stopped to detect
the printers on its own and now uses avahi/mdns.
It hasn't been thought of a cfengine configuration item that purges exactly
this package. (The item had been added way back in 2010 to fix a then
existing LDAP related problem.)
The fix is simply to adjust cf/cf.ldapclient.