Fix method of capturing data (include seconds with no incoming data)

[alagoa]

The tool that needs to be fixed is the pcap.py
Currently the data is captured only when there is incoming data, which means that there will be no lines with '0s' in the captures.
For example, currently the capture file turns out like this:
40
30
2
3
13

When in reality it should be:

40
0
30
2
3
0
0
13

In other words, each line should represent a second of incoming data even if the data is 0.