Bug#884835: mailman3-suite: postinst fails if nginx is installed and apache2 is missing

[Philip Frei]

Package: mailman3-suite
Version: 0+20170523-6
Severity: normal

Hi,

it's possible to use mailman3 with nginx. But without Apache2 installed
the postinst will fail because there's no instruction how to proceed
with nginx.

regard,
Phil