Link the default Apache directory to the Nextcloud server in all runners

In order to run the acceptance tests in Apache "/var/www/html" has to be
linked to the root directory of the Nextcloud server. Before this was
automatically done when launching the acceptance tests through
"./run.sh", but an explicit command was needed when run in Drone. Now
the linking was moved from "run.sh" to "run-local.sh", so it is
automatically done when run through "./run.sh" and in Drone, including
when running the tests for an app instead of for the server.

Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>