Comment 1 for bug 1324062

Some discussion with upstream nginx here: https://github.com/openresty/lua-nginx-module/issues/343

"If as you said there are quite a few people already using ngx_lua + lua 5.1, then linking against Lua 5.2 will probably break these people's existing Lua code. Lua 5.2 is essentially an incompatible different language."