fix test

Author: Revolyssup

t/request-id-err-log.t

@@ -7,8 +7,8 @@ __DATA__
 === TEST 1: request_id in error log set
 --- config
     location /t {
-				set $request_id 1234;
-        apisix_request_id_var $request_id;
+		set $request_id_new 1234;
+        apisix_request_id_var $request_id_new;
         content_by_lua_block {
             ngx.log(ngx.INFO, "log_msg")
             ngx.exit(200)