New GitHub label for release blockers

[Dr. Matthias St. Pierre]

> when your time permits, could you please double-check whether all important tickets
> for beta1 were moved correctly from '3.0.0' to '3.0.0 beta1'?

The '3.0 New Core + FIPS' project currently lists 21 open pull requests,

[is:open is:pr project:openssl/openssl/2]:
	https://github.com/openssl/openssl/pulls?q=is%3Aopen+is%3Apr+project%3Aopenssl%2Fopenssl%2F2+

ten of which are not associated with any milestone yet

[is:open is:pr project:openssl/openssl/2 no:milestone]:
	https://github.com/openssl/openssl/pulls?q=is%3Aopen+is%3Apr+project%3Aopenssl%2Fopenssl%2F2+no%3Amilestone

It would be helpful if someone of the core team could check and assigne them.

Matthias