Add the 'pending 0' end flag

[rekansneb]

issue 1

During the passive scanning process, the end flag can clearly indicate whether the current task has ended.

wscan log

scanned: 48, pending: 1, requestSent: 24072, latency: 215.762466ms, failedRatio: 0.000000%
scanned: 48, pending: 1, requestSent: 24072, latency: 215.762466ms, failedRatio: 0.000000%
scanned: 48, pending: 1, requestSent: 24072, latency: 215.762466ms, failedRatio: 0.000000%
scanned: 48, pending: 1, requestSent: 24072, latency: 215.762466ms, failedRatio: 0.000000%
scanned: 48, pending: 1, requestSent: 24072, latency: 215.762466ms, failedRatio: 0.000000%
scanned: 48, pending: 1, requestSent: 24072, latency: 215.762466ms, failedRatio: 0.000000%
scanned: 48, pending: 1, requestSent: 24072, latency: 215.762466ms, failedRatio: 0.000000%
scanned: 48, pending: 1, requestSent: 24072, latency: 215.762466ms, failedRatio: 0.000000%
scanned: 48, pending: 1, requestSent: 24072, latency: 215.762466ms, failedRatio: 0.000000%
scanned: 48, pending: 1, requestSent: 24072, latency: 215.762466ms, failedRatio: 0.000000%

---

x*** log

scanned: 40, pending: 4, requestSent: 9172, latency: 230.46ms, failedRatio: 0.00%
scanned: 41, pending: 3, requestSent: 9241, latency: 230.48ms, failedRatio: 0.00%
scanned: 43, pending: 1, requestSent: 9263, latency: 229.71ms, failedRatio: 0.00%
All pending requests have been scanned
scanned: 44, pending: 0, requestSent: 9263, latency: 227.57ms, failedRatio: 0.00%

issue 2

According to observation, when listening is enabled and no request is received, the pending task is 1. Can I cancel this output.

[*] scanned: 0, pending: 1, requestSent: 0, latency: 0.000000ms, failedRatio: 0.000000%