openssl/gnutls: rectify the TLS version checks for QUIC

openssl/gnutls: rectify the TLS version checks for QUIC

The versions check wrongly complained and return error if the *minimum*
version was set to something less than 1.3. QUIC is always TLS 1.3, but
that means minimum 1.2 is still fine to ask for.

This also renames the local variable to make the mistake harder to make
in the future.

Regression shipped in 8.8.0

Follow-up to 3210101088dfa3d6a125

Reported-by: fds242 on github
Fixes #13799
Closes #13802