Tighten the config block rules.

Currently the 403 LB blockBlock Block is the abstract term used to describe units of markup that, composed together, form the content or layout of a webpage using the WordPress editor. The idea combines concepts of what in the past may have achieved with shortcodes, custom HTML, and embed discovery into a single consistent API and user experience. for config is being too greedy. Can we please tighten it up to allow legitimate urls such as these through?

https://wordpress.org/support/users/sconfig/, https://profiles.wordpress.org/sconfig/

Ref: #4776-meta