Memory leak

[k79e]

It use around 40MB at first
But after 4min it's 90M now.
160M after 9min

I'm using v0.7 on debian x64

It reproduced when using cl=20,CL=128,at=4,cd=50ms with 200 connections limit
or CL=256 with 400 connections limit.

tested it again with smaller CL and it's same

   PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
   878 root      20   0   46000  42688   6276 R  36.0   9.1   0:46.86 ncrack
   878 root      20   0   53740  50428   6276 R  36.0  10.7   1:08.18 ncrack
   878 root      20   0   69744  66292   6276 R  40.0  14.1   2:17.70 ncrack

I'm using ssh module

Same for win
At start it's 30-40m and 15min after it's 90M now.
(ncrack --user root --save save -P pw.txt -m ssh:cl=20,CL=200,at=4,cd=50ms -p ssh -iL iplist/list.txt --connection-limit 400 --append-output -oN ooo)

Now cpu is ~15% but I remember in previous freeze #103 it's using 25% which is a full core.

It's using 186M@32min
289M@45min+ and still increasing