Fix sharkjack.sh

[MrMan1994]

Fix shark jack interface not getting detected. Grepping the ip and invert grepping (grep -v) the same ip cannot return anything (unless -A is set to greater than 1), thus $IFACE is always empty.

[tmossey]

Unfortunately I'm not getting the same results.

The current version returns:

$ ip route show to match 172.16.24.1 2>/dev/null| grep -i 172.16.24.1 | cut -d ' ' -f3 | grep -v 172.16.24.1

enp0s25

which is the intended result.

However this change returns:

$ ip route show to match 172.16.24.1 2>/dev/null| grep -i 172.16.24.1 | cut -d ' ' -f3

172.16.24.1
enp0s25

Here $IFACE isn't empty in either, but the current version results in the desired return value.

[MrMan1994]

Alright, it seems as if I'm missing a route as only the IP is shown. Though I wonder how I got it to work in the first place... But how do I add that route? I can't get it to work neither ways anymore...