lws/mbedtls-wrapper: Align SSL_CTX_new function declaration with OpenSSL

[ThePassionate]

SSL_CTX *SSL_CTX_new(const SSL_METHOD *meth) is the declaration of openssl.
We hope that the OpenSSL interface in mbedtls-wrapper can also align with the OpenSSL real declaration.

[lws-team]

/home/sai/jobs/85984169/src/ebuild/esp-heltec-wb32/libwebsockets/lib/tls/mbedtls/wrapper/library/ssl_lib.c: In function 'SSL_CTX_new':
/home/sai/jobs/85984169/src/ebuild/esp-heltec-wb32/libwebsockets/lib/tls/mbedtls/wrapper/library/ssl_lib.c:208:25: error: 'rngctx' undeclared (first use in this function)
  208 |     cert = ssl_cert_new(rngctx);

... did you build-test it?

[ThePassionate]

/home/sai/jobs/85984169/src/ebuild/esp-heltec-wb32/libwebsockets/lib/tls/mbedtls/wrapper/library/ssl_lib.c: In function 'SSL_CTX_new':
/home/sai/jobs/85984169/src/ebuild/esp-heltec-wb32/libwebsockets/lib/tls/mbedtls/wrapper/library/ssl_lib.c:208:25: error: 'rngctx' undeclared (first use in this function)
  208 |     cert = ssl_cert_new(rngctx);

... did you build-test it?

Sorry, I had the mbedtls backend misconfigured in my compilation tests. The latest patch is now updated - could you please review and test it again? Thanks a lot!