MINOR: quic: Make ->set_encryption_secrets() be callable two times

MINOR: quic: Make ->set_encryption_secrets() be callable two times

With this patch, ha_set_encryption_secrets() may be callable two times,
one time to derive the RX secrets and a second time to derive the TX secrets.

There was a missing step to do so when the RX secret was received from the stack.
In this case the secret was not stored for the keyupdate, leading the keyupdate
RX part to be uninitialized.

Add a label to initialize the keyupdate RX part and a "goto" statement to run
the concerned code after having derived the RX secrets.

This patch is required to make the keupdate feature work with the OpenSSL wrapper.

Must be backported as far as 2.6.