modify from http folder (#1470)

* delete unused var and add used arg

* use interface from stream

lualib/http/tlshelper.lua

@@ -77,7 +77,6 @@ function tlshelper.writefunc(fd, tls_ctx)
 end
 
 function tlshelper.readallfunc(fd, tls_ctx)
-    local readfunc = socket.readfunc(fd)
     return function ()
         local ds = socket.readall(fd)
         local s = tls_ctx:read(ds)