The hardcoded connection timeout of 5 seconds may not be enough in some
cases, so now it is got from the ObjectStore arguments in Nextcloud
configuration, falling back to 5 if not set.
The connection timeout is set in seconds, but decimal precision can be
used for subsecond accuracy (for example, 4.2 for 4200 milliseconds).
Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>