reCaptcha: allow for all domains or add via API

ReCaptcha actually allows you to add up to 50 domains, all domains must be on a new line in the domain input box.

Domain registration also includes any and all sub-domains.

If necessary, you can disable domain name checking but it is highly discouraged since doing so creates a considerable security hole.

Google reCaptcha doc about domains: Domain/Package Name Validation _{^{(link updated)}}

For multiple domains you can use the Secure Token method. Secure Token (Deprecated)

A reCAPTCHA key is normally tied to a set of individual domains. However, if your list of valid domains is extremely long, fluid, or unknown, we give you the option to turn off the domain name checking on reCAPTCHA's end, and instead check on your server.

https://developers.google.com/recaptcha/docs/domain_validation