Repeated end events did not properly disconnect

[Canees]

Problem description:
It disconnects correctly the first time.
When I connect a second time, do end again and it doesn't disconnect.

Use version:
latest version

expect:
It can disconnect correctly

fragment:
`
const sleep = (ms) => new Promise(res => setTimeout(res, ms));
const a = mqtt.connect('mqtt://127.0.0.1:49800', { username: 'test', password: 'test',manualConnect:true})
a.connect()
await sleep(5000)
a.end() //It disconnects correctly

await sleep(3000)
a.connect() //It connects correctly

await sleep(1000)
a.end() // It does not disconnect correctly
`

[robertsLando]

After calling end you should recreate a new instance, end it's like destroy, it removes some listeners and other stuff that make the instance not usable anymore

[Canees]

After calling end you should recreate a new instance, end it's like destroy, it removes some listeners and other stuff that make the instance not usable anymore

Yes, I have modified it. It always feels strange. Perhaps it is not semantic enough? Like new connect()?

[robertsLando]

Yeah but I keep all this stuff for v6. See #1648