Error handling and critical error fix

[TobyX424242]

• Fixed a critical error in config.go.
  As explained in Document, original function didn't accept any parameters. Replaced it with appropriate 24 * time.Hour to represent 24 hours
• Implemented Error handling for various cases instead of drop them silently

[SourLemonJuice]

For the time.Duration error in config.go, that does a critical bug, but not because it didn't accept any parameter, but Go actually consider the receiver as the first parameter of that function, they can be swapped even:

time.Hour.Hours()
// ==
time.Hours(time.Hour)

Also, the 24 is an integer, which also the base type of time.Duration, so the compiler missed this before.
This is the first time I know this behavior, thank you for that.

But for the other error checks, I don't really want to grow too much complexity for a Go project, and also the selector.go is under heavy development. So sorry, I can't merge almost code of this PR.

For some other critical bug fixes, they will be added into the next release, like the error check of router.SetTrustedProxies, I really missed this bug :(