set_timeout in plugin causes crash

[tw4452852]

I use set_timeout in the plugin's load, but it triggers a crash when the timer expired with the following backtrace:

Error occured in server:
Originating Thread(s):

Error: thread 'unnamed' panicked at 'called Option::unwrap() on a None value': zellij-server/src/wasm_vm.rs:281
   0: zellij_utils::errors::handle_panic
   1: std::panicking::rust_panic_with_hook
             at /rustc/53fd98ca776cb875bc9e5514f56b52eb74f9e7a9/library/std/src/panicking.rs:626:17
   2: std::panicking::begin_panic_handler::{{closure}}
             at /rustc/53fd98ca776cb875bc9e5514f56b52eb74f9e7a9/library/std/src/panicking.rs:517:13
   3: std::sys_common::backtrace::rust_end_short_backtrace
             at /rustc/53fd98ca776cb875bc9e5514f56b52eb74f9e7a9/library/std/src/sys_common/backtrace.rs:141:18
   4: rust_begin_unwind
             at /rustc/53fd98ca776cb875bc9e5514f56b52eb74f9e7a9/library/std/src/panicking.rs:515:5
   5: core::panicking::panic_fmt
             at /rustc/53fd98ca776cb875bc9e5514f56b52eb74f9e7a9/library/core/src/panicking.rs:92:14
   6: core::panicking::panic
             at /rustc/53fd98ca776cb875bc9e5514f56b52eb74f9e7a9/library/core/src/panicking.rs:50:5
   7: std::sys_common::backtrace::rust_begin_short_backtrace
   8: core::ops::function::FnOnce::call_once{{vtable.shim}}
   9: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
             at /rustc/53fd98ca776cb875bc9e5514f56b52eb74f9e7a9/library/alloc/src/boxed.rs:1572:9
      <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
             at /rustc/53fd98ca776cb875bc9e5514f56b52eb74f9e7a9/library/alloc/src/boxed.rs:1572:9
      std::sys::unix::thread::Thread::new::thread_start
             at /rustc/53fd98ca776cb875bc9e5514f56b52eb74f9e7a9/library/std/src/sys/unix/thread.rs:74:17
  10: start_thread
             at /builddir/glibc-2.32/nptl/pthread_create.c:463:8
  11: GI_clone
             at /builddir/glibc-2.32/misc/../sysdeps/unix/sysv/linux/x86_64/clone.S:95

[TheLostLambda]

Fixed by #665 !