Attackers can crash whole node by panicking a single thread

[SWvheerden]

A panic on a thread will cause the whole process to be aborted. This happens both
in the wallet and in the base node.

fn main() {
// Setup a panic hook which prints the default rust panic message
but also exits the process. This makes a panic in
// any thread "crash" the system instead of silently continuing.
let default_hook = panic::take_hook();
panic::set_hook(Box::new(move |info| {
default_hook(info);
process::exit(1);
}));

This design decision allowed several vulnerabilities in this report to be of critical
severity. For example, panics on RPC requests would have practically no impact
when their thread panics instead of being a tool for triggering a denial of service on
the whole network.

Panics on threads should be treated as bugs and fixed, but an attacker would have
a much harder time converting them to successful exploits if the program did not
crash immediately.