OpenSSL should ignore missing config file

When initializing OpenSSL in v1.1.0 or later, tell OpenSSL to ignore missing openssl.cnf. Fixes alanxz#523

Author: alanxz

librabbitmq/amqp_openssl.c

@@ -584,8 +584,9 @@ static int setup_openssl(void) {
  CRYPTO_set_locking_callback(ssl_locking_callback);
 
 #ifdef AMQP_OPENSSL_V110
- if (CONF_modules_load_file(NULL, "rabbitmq-c", CONF_MFLAGS_DEFAULT_SECTION) <=
- 0) {
+ if (CONF_modules_load_file(
+ NULL, "rabbitmq-c",
+ CONF_MFLAGS_DEFAULT_SECTION | CONF_MFLAGS_IGNORE_MISSING_FILE) <= 0) {
  status = AMQP_STATUS_SSL_ERROR;
  goto out;
  }