Improve SSL error messages on install / update

Improve the checks introduced by !1173 (merged)

The installer should print out any reasons that no certificate will be issued or that issuing certificate failed.

changed milestone to %3.2

added Feature Request label

created merge request !1181 (merged) to address this issue

mentioned in merge request !1181 (merged)

closed with merge request !1181 (merged)

mentioned in commit 5f31eb1e

added Implemented label