sometimes sched dict do not contains con key

I just updated to 1.2.4 and I wasn't receiving mail notifications when hosts/services were going UP or DOWN anymore.

I started looking in logs and found the following:

```
File "/usr/local/shinken/src/shinken/shinken/satellite.py", line 613, in get_new_actions
    con = sched['con']
KeyError: 'con'
```

in most services.

I don't know if this used to work < 1.2.4.

But I applied this patch, restarted services and my inbox was filled with notifications.