#28 Fix Portscan.py default case

As briefly discussed in the meeting, the default case (when not specifying any parameters) in the portscan-attack only scanned 891 ports instead of the 1000 it was supposed to. The problems I found are two off-by-one errors in line 101 and 102: when using range(0,9) the generated numbers don't include the nine, the same goes for the array slicing. This resulted in 9*99=891 packets being generated instead of 1000.