Using colon on Topic name cause Tokio panic

[hariangr]

This code

export const topicPostingCreated = new Topic<PostingCreatedEvent>("posting:created", {
  deliveryGuarantee: 'at-least-once'
})

cause this unfriendly error

thread '<unnamed>' panicked at runtimes/core/src/pubsub/nsq/sub.rs:40:65:
called `Option::unwrap()` on a `None` value
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
fatal runtime error: failed to initiate panic, error 5

Changing that code into

export const topicPostingCreated = new Topic<PostingCreatedEvent>("posting-created", {
  deliveryGuarantee: 'at-least-once'
})

I believe a better error message should be used, and the error should never happen at the runtime dependency level (Tokio.rs)