BUG/MINOR: ssl: leak in ssl-f-use

Fix the leak of the filename in the struct cfg_crt_node which is a
temporary structure used for ssl-f-use initialization.

Must be backported to 3.2.

src/cfgparse-ssl.c

@@ -2405,6 +2405,7 @@ error:
 	ha_free(&ckch_conf);
 	ssl_sock_free_ssl_conf(ssl_conf);
 	ha_free(&ssl_conf);
+	ha_free(&cfg_crt_node->filename);
 	ha_free(&cfg_crt_node);
 	return -1;
 }
@@ -2460,6 +2461,7 @@ static int post_section_frontend_crt_init()
 		LIST_DELETE(&n->list);
 		/* n->ssl_conf is reused so we don't free them here */
 		free(n->ckch_conf);
+		free(n->filename);
 		free(n);
 	}