Unintuitive handling of 0 min and max for jitter backoff

[ubersan]

Currently 0 min and max wait times for jittered backoff automatically fall back to the defaults, see here: https://github.com/go-resty/resty/blob/v3/retry.go#L82-L87 I think this is quite unintuitive.

Maybe one can argue that jitter with 0 backoff between doesn't make sense, but it would be a convenient way to get a constant delay without needing to set a custom stragegy, i.e. by setting wait time and max wait time both to 0.