ttl fix

Signed-off-by: Abhishek Choudhary <shreemaan.abhishek@gmail.com>

Author: shreemaan-abhishek

apisix/plugins/limit-req/util.lua

@@ -57,8 +57,7 @@ function _M.incoming(self, red, key, commit)
     end
 
     if commit then
-        -- limit-req does rate limiting per second, so we set the ttl to 2 seconds
-        local ttl = 2
+        local ttl = math.ceil(self.burst / self.rate) + 1
         local ok, err
 
         ok, err = red:set(excess_key, excess, "EX", ttl)