logsrvd_relay_tls_ctx: Do not fall back on server TLS context

If a TLS-capable relay is enabled, logsrvd_config->relay.ssl_ctx
will be set.  Unlike the relay TLS settings, there is no reason to
fall back on the main server TLS context if there is no relay TLS
context.

Found by the ZeroPath AI Security Engineer <https://zeropath.com>

Author: millert

logsrvd/logsrvd_conf.c

@@ -334,9 +334,7 @@ logsrvd_conf_relay_retry_interval(void)
 SSL_CTX *
 logsrvd_relay_tls_ctx(void)
 {
-    if (logsrvd_config->relay.ssl_ctx != NULL)
-	return logsrvd_config->relay.ssl_ctx;
-    return logsrvd_config->server.ssl_ctx;
+    return logsrvd_config->relay.ssl_ctx;
 }
 
 bool