This fixes the following error in zope:

bash-5.1$ slapos node tail slappart6:zope-0-7b91211283be978a19e1bb10e54dc284-on-watch
e76946300062f86fcc7/eggs/haufe.requestmonitoring-0.6.0-py3.8.egg/haufe/requestmonitoring/monitor.py", line 28, in <module>
    from zope.app.appsetup.interfaces import IProcessStartingEvent
  File "/srv/slapgrid/slappart45/srv/runner/software/6afc47a0c1078e76946300062f86fcc7/eggs/zope.app.appsetup-3.16.0-py3.8.egg/zope/app/appsetup/__init__.py", line 20, in <module>
    from zope.app.appsetup.appsetup import config, database
  File "/srv/slapgrid/slappart45/srv/runner/software/6afc47a0c1078e76946300062f86fcc7/eggs/zope.app.appsetup-3.16.0-py3.8.egg/zope/app/appsetup/appsetup.py", line 29, in <module>
    class SystemConfigurationParticipation(object):
  File "/srv/slapgrid/slappart45/srv/runner/software/6afc47a0c1078e76946300062f86fcc7/eggs/zope.app.appsetup-3.16.0-py3.8.egg/zope/app/appsetup/appsetup.py", line 30, in SystemConfigurationParticipation
    zope.interface.implements(IParticipation)
  File "/srv/slapgrid/slappart45/srv/runner/software/6afc47a0c1078e76946300062f86fcc7/eggs/zope.interface-5.4.0-py3.8-linux-x86_64.egg/zope/interface/declarations.py", line 778, in implements
    raise TypeError(_ADVICE_ERROR % 'implementer')
zope.configuration.xmlconfig.ZopeXMLConfigurationError: File "/srv/slapgrid/slappart45/srv/runner/software/6afc47a0c1078e76946300062f86fcc7/eggs/haufe.requestmonitoring-0.6.0-py3.8.egg/haufe/requestmonitoring/monitor.zcml", line 5.2-5.49
    File "/srv/slapgrid/slappart45/srv/runner/instance/slappart6/srv/erp5shared/etc/site.zcml", line 26.2-26.66
    TypeError: Class advice impossible in Python3.  Use the @implementer class decorator instead.

zope.app.appsetup 4.2.0 is the first version which supports py3.8:

  https://pypi.org/project/zope.app.appsetup/4.2.0/#section-1

We currently use python 3.8:

[1] https://lab.nexedi.com/nexedi/slapos/blob/d2404ed9/stack/erp5/buildout-py3.cfg#L36
[2] https://lab.nexedi.com/nexedi/slapos/blob/7d78a928c09b63508c69f84aa499a9870b3ae37e/component/python3/buildout.cfg#L21

caddy-frontend-N is bad name, it's just frontend-node-N.

This option was useful only during the time, when there were experiments
running on caddy-frontend clusters during switch to HTTP/2.

Currently HTTP/2 is a standard, and there is no reason to disable it globally.

Attention, this change will require manual intervention on the upgraded
cluster with:

sed -i 's/^recipe = caddyprofiledeps/recipe = software/g' .installed*

On each partition.

NAME_BASE is set on top of the file with informative warning, so that
developers are aware of consequences.

instance-slave-caddy-simplified-input-schema.json has been removed, as it is
not useful.

Some profiles were templates and vice versa, which was very
misleading.

The most complex case - no automatic https redirection and usage
of url and https-url is used to check implementation of type:redirect now.

haufe.requestmonitoring already supports WSGI and Python3 and seems
used and maintainted.

3.7.3 is an "urgent" new release as announced in
https://www.postfix.org/announcements/postfix-3.7.3.html
the old 3.7.2 version seem to have bee removed from mirrors
(see http://postfix.mirrors.ovh.net/postfix-release/official/ for a
mirror with directory index) and was not in shacache.