Increase interfaces limit to 4096

Hello,

Hping3 fails to lookup for interfaces with index greater to 16 because the internal buffer to store interfaces is 16 entries large.
This result in hping3 not being usable for interfaces after this limit.
On todays computers we can have way more interfaces.
Can you increase the limit to a higher value (like 4096 for example) ?

In file 'getifname.':
`- struct ifreq ibuf[16],`
`+ struct ifreq ibuf[4096],`