BUG/MINOR: http-htx: Don't forget to release the http reply in release function

The http reply must be released in the function responsible to release it. This
leak was introduced when the http return was refactored to use http reply.

This patch should partly fix the issue #645.

No backport needed.

src/http_htx.c

@@ -993,6 +993,7 @@ void release_http_reply(struct http_reply *http_reply)
 			free(lf);
 		}
 	}
+	free(http_reply);
 }
 
 static int http_htx_init(void)