Remove password from state inspection

[magnetised]

Fixes #1718

[alco]

@magnetised I have a different take on the same issue - #1772. IMO, it's better to keep the password obfuscated in memory, makes it more resilient to future code changes where we rename the connection manager module or move the connection logic into a different one. It also works in cases where the Inspect protocol is not used to print the process state, such as the case with :io.format('~p', [...]), for example.