Previously, rec.level field was not uninitialized in SSL_provide_quic_data().
As a result, its value was always ssl_encryption_initial. Later in
ngx_quic_ciphers() such level resulted in resetting the cipher to
TLS1_3_CK_AES_128_GCM_SHA256 and using AES128 to encrypt the packet.
Now the level is initialized and the right cipher is used.