'wendelin.core' needs to differentiate between a NEO cluster with SSL
and without SSL from a normalized zurl (e.g. a zurl which doesn't
contain any paths to encryption files). Therefore the 'neo' / 'neos'
scheme difference was introduced in nexedi/neoppod@bc3e38ea.
This patch introduces this difference in zurl that SlapOS provides for
'wendelin.core' - this essentially fixes a ERP5+WCFS setup that connects
to a NEO cluster with activated SSL.

/reviewed-by @kirr @jerome
/reviewed-on nexedi/slapos!1620