[bitcoinabc.org] Remove rest.kingbch.com

Summary:
Remove rest.kingbch.com tile from developer infra.

This was the last instance of bch-api still running. bch-api is no longer used by any apps and is obsoleted by chronik.

Test Plan: Confirm the tile is removed

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Klakurka, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D14400