fix ctx usage in reverse proxy + remove useless log in limit

src/common/core/limit/limit.lua

@@ -62,7 +62,6 @@ function limit:init()
 	if variables == nil then
 		return self:ret(false, err)
 	end
-	self.logger:log(ngx.ERR, cjson.encode(variables))
 	-- Store URLs and rates
 	local data = {}
 	local i = 0

src/common/core/reverseproxy/reverseproxy.lua

@@ -21,7 +21,7 @@ function reverseproxy:header()
   end
   -- Add reverseproxy client headers
   for srv, vars in pairs(variables) do
-    if srv == ngx.ctx.bw.server_name then
+    if srv == self.ctx.bw.server_name then
       for var, value in pairs(vars) do
         if utils.regex_match(var, "REVERSE_PROXY_HEADERS_CLIENT") and value then
           local iterator, err = ngx.re.gmatch(value, "([\\w-]+) ([^;]+)")