Increase timeout in remoteFileHandlerTests:PoolHandlerTests.testStop

On congested hosts (like the oVirt Jenkins host) the test might fail
even though nothing is broken it is just taking longer then expected.

Change-Id: I9334cf00c37b352adad52a0587f9675cda5bd0dd
Signed-off-by: Saggi Mizrahi <smizrahi@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/10637
Reviewed-by: Vinzenz Feenstra <vfeenstr@redhat.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>
Tested-by: Dan Kenigsberg <danken@redhat.com>