Document logger category for default security password

[sbrannen]

The reference manual states that the default security password will be logged at INFO log level, but it does not mention what the logger category is.

Thus if you fine tune your logging settings such that the default security password is no longer logged, you literally have to search through the source code to discover that the category is org.springframework.boot.autoconfigure.security.

So please document this in the reference manual.

[sbrannen]

While you're at it, could please delete the second newline (\n) that is appended to the log statement for the default security password in BootDefaultingAuthenticationConfigurerAdapter?

The logging framework appends a newline in any case. So having 3 newlines after the log statement is unnecessary.

[sbrannen]

Thanks! :)