[Tile-serving] [openstreetmap/osm2pgsql] Fix various unused parameter issues and enable -Wextra on travis (#906)

[Sarah Hoffmann]

Appveyor is just confused that is has built the PR twice and errored out on artefact generation. That's safe to ignore.

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/openstreetmap/osm2pgsql/pull/906#issuecomment-462111319
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/tile-serving/attachments/20190209/5db67245/attachment.html>