incremental campaigns do not work with valid values

[jrbalderrama]

For the example below the incremental campaign does not work for the second iteration including valid values in the zip group (1,1, 100,0) because the condition for test_case_1 lets pass the case when nbr_clients >= nbr_servers. The execution does not iterate over any group and finishes after inventory.

campaign:
  test_case_1:
    nbr_clients: [1, 1]
    nbr_servers: [2, 1]
    nbr_calls: [100, 100]
    pause: [0, 0]
    ...

[jrbalderrama]

It was already addressed in other commit