Fix an issue when polling from redis for the first time and the tag of first message in the redis queue is not 0, it always become 0 in the memory queue
Fix an issue when polling from redis for the first time and the tag of first message in the redis queue is not 0, it always become 0 in the memory queue

slact/nginx_http_push_module,slact/nginx_http_push_module,slact/nginx_http_push_module,slact/nginx_http_push_module