add local var

Author: loveshell

waf.lua

@@ -1,5 +1,6 @@
 local content_length=tonumber(ngx.req.get_headers()['content-length'])
 local method=ngx.req.get_method()
+local ngxmatch=ngx.re.match
 if whiteip() then
 elseif blockip() then
 elseif denycc() then