[BUG] dkg_gadget::worker panics on `start_keygen`

[dutterbutter]

Describe the bug

When attempting to run a second collator to begin dkg-keygen, it immediately panics. The parachain connects to the relaychain and other collator fine.

To Reproduce
Steps to reproduce the behavior:

1. Follow README.md instructions.

Log output

Log Output

Version: 3.0.0-76409c2-aarch64-macos

 0: backtrace::backtrace::trace
 1: backtrace::capture::Backtrace::new
 2: sp_panic_handler::set::{{closure}}
 3: std::panicking::rust_panic_with_hook
           at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/std/src/panicking.rs:610:17
 4: std::panicking::begin_panic_handler::{{closure}}
           at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/std/src/panicking.rs:500:13
 5: std::sys_common::backtrace::__rust_end_short_backtrace
           at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/std/src/sys_common/backtrace.rs:139:18
 6: rust_begin_unwind
           at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/std/src/panicking.rs:498:5
 7: core::panicking::panic_fmt
           at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/core/src/panicking.rs:107:14
 8: core::panicking::panic
           at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/core/src/panicking.rs:48:5
 9: dkg_gadget::worker::DKGWorker<B,C,BE>::process_block_notification
10: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
11: <futures_util::future::future::map::Map<Fut,F> as core::future::future::Future>::poll
12: <sc_service::task_manager::prometheus_future::PrometheusFuture<T> as core::future::future::Future>::poll
13: <futures_util::future::select::Select<A,B> as core::future::future::Future>::poll
14: <tracing_futures::Instrumented<T> as core::future::future::Future>::poll
15: tokio::park::thread::CachedParkThread::block_on
16: tokio::runtime::handle::Handle::block_on
17: tokio::runtime::task::core::CoreStage<T>::poll
18: tokio::runtime::task::harness::Harness<T,S>::poll
19: tokio::runtime::blocking::pool::Inner::run
20: std::sys_common::backtrace::__rust_begin_short_backtrace
21: core::ops::function::FnOnce::call_once{{vtable.shim}}
22: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
           at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/alloc/src/boxed.rs:1694:9
    <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
           at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/alloc/src/boxed.rs:1694:9
    std::sys::unix::thread::Thread::new::thread_start
           at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/std/src/sys/unix/thread.rs:106:17
23: __pthread_deallocate


Thread 'tokio-runtime-worker' panicked at 'called `Option::unwrap()` on a `None` value', /Users/dut/.cargo/git/checkouts/dkg-substrate-0264706d690306a8/73a23c4/dkg-gadget/src/worker.rs:430

Expected behaviour

Upon starting a second collator, I expect the collator to connect with the first collator and being the dkg keygen process.

Screenshots

Environment (please complete the following information):

• OS: - aarch64-macos
• Rust version(e.g. rustc --version): nightly-2021-11-20-aarch64-apple-darwin
• Branch/commit: main

Other information and links