BUG/MINOR: haproxy: fix rule->file memory leak

When using the "use_backend" configuration directive, the configuration
file name stored as rule->file was not freed in some situations. This
was introduced in commit 4ed1c95 ("MINOR: http/conf: store the
use_backend configuration file and line for logs").

This patch should be backported to 1.9, 1.8 and 1.7.

src/haproxy.c

@@ -2223,8 +2223,8 @@ void deinit(void)
 			if (rule->cond) {
 				prune_acl_cond(rule->cond);
 				free(rule->cond);
-				free(rule->file);
 			}
+			free(rule->file);
 			free(rule);
 		}