Optimize IsBanned() #29

IsBanned is called very often in p2p code, this change optimizes it to be faster. Originally by BTC Core and recently pulled into ZEC:

c1600cd259

Not sure the best way to test a change like this -> It builds, it runs, and I can use hush-cli RPC without it crashing.

@jahway603 have you tried banning an IP (setban) and looking at banned IP's (listbanned) via hush-cli ?

@duke Does this mean it's working fine?

wtf@wtf:~/dev/hush3$ ./src/hush-cli listbanned
[
]
wtf@wtf:~/dev/hush3$ ./src/hush-cli setban 1.2.3.4/32 add 0
wtf@wtf:~/dev/hush3$ ./src/hush-cli listbanned
[
  {
    "address": "1.2.3.4/255.255.255.255",
    "banned_until": 1657983851,
    "time_remaining": 86398
  }
]
wtf@wtf:~/dev/hush3$ ./src/hush-cli setban 1.2.3.4/32 remove
wtf@wtf:~/dev/hush3$ ./src/hush-cli listbanned
[
]

PR has been merged