job main loop: another round of functional test timeout adjustment

Looks like a travis worker can be a lot slower than I thought at first,
in the order of 50 times slower than a 2 year old development machine.

So now, the timeout is 250 times higher than the test run would take
under the mentioned development machine (0.12s), but still able to
catch bugs if the loop does not cycle immediatelly on failure for the
100 failtests.

Signed-off-by: Cleber Rosa <crosa@redhat.com>