NGINX 1.18 compatibility problem

[imihajlow]

When connecting to a NGINX 1.18 server with embedded-tls (features = ["async", "defmt"]), server rejects the connection with Handshake Failed. The error message on the server is following:

SSL_do_handshake() failed (SSL: error:14201076:SSL routines:tls_choose_sigalg:no suitable signature algorithm) while SSL handshaking

Addition of Session ID, as mentioned in #57, does not help.

However, commenting out line 113 of config.rs (adding more signature schemes to the config, despite not having the alloc feature) solves the issue.

User code reproducing the problem: https://github.com/imihajlow/ethernet-to-spi/blob/b62dd533e5da056bc3f1ffe15e70d248cfbafab1/stm32eth-f401/src/tls_task.rs