Add Page: Custom entity page triggers unresolvable validation error

[Joel Mitchell]

When adding a page of type "custom entity page", the following validation error occurs:

Custom entity details pages should not specify a Url Path, instead they should specify a Routing Rule.

However, the Url Path cannot be edited in the UI. This is likely because the field is being automatically populated when entering a title.

[Joel Mitchell]

Fixed, will be released in v0.11.1