Rerun ends up with an orphaned window when it fails to bind to a tcp port

[jleibs]

To repo, run a script that includes rr.init(..., spawn=True) twice.

Previous behavior:

Console would show:

[2023-03-21T13:34:49Z WARN  rerun::run] Failed to bind TCP address "0.0.0.0:9876" for our WS server.. Another Rerun instance is probably running.

And no window would be launched.

Current behavior:

We get a stack trace but the window still comes up.

thread 'tokio-runtime-worker' panicked at 'called `Result::unwrap()` on an `Err` value: Failed to bind TCP address "0.0.0.0:9876"

Caused by:
    Address already in use (os error 98)', re_sdk_comms/src/server.rs:42

   6: core::panicking::panic_fmt
             at core/src/panicking.rs:64:14
   7: core::result::unwrap_failed
             at core/src/result.rs:1791:5
   8: core::result::Result<T,E>::unwrap
             at core/src/result.rs:1113:23
      re_sdk_comms::server::listen_for_new_clients::{{closure}}
             at re_sdk_comms/src/server.rs:39:20
   9: tokio::runtime::task::core::Core<T,S>::poll::{{closure}}
             at tokio-1.24.1/src/runtime/task/core.rs:223:17
      tokio::loom::std::unsafe_cell::UnsafeCell<T>::with_mut
             at tokio-1.24.1/src/loom/std/unsafe_cell.rs:14:9
      tokio::runtime::task::core::Core<T,S>::poll
             at tokio-1.24.1/src/runtime/task/core.rs:212:13
  10: tokio::runtime::task::harness::poll_future::{{closure}}

Appears to be a regression related to: 7c36951