[ssr-caching] Only cache 200 status requests (#3708)
[ssr-caching] Only cache 200 status requests (#3708)

* [ssr-caching] Only cache 200 requests

I'm assuming caching an error page is a bad pattern.

* Update server.js

flybayer/next.js,zeit/next.js,BlancheXu/test,JeromeFitz/next.js,BlancheXu/test,JeromeFitz/next.js,JeromeFitz/next.js,azukaru/next.js,BlancheXu/test,flybayer/next.js,JeromeFitz/next.js,flybayer/next.js,azukaru/next.js,azukaru/next.js,azukaru/next.js,zeit/next.js,zeit/next.js,flybayer/next.js