fix: client->body set input values
fix: client->body set input values

fix write_body2mem -
* rb_strconcat never works for void* client->body...

set StringIO object to client->body when BODY_TYPE_BUFFER

prepare_call_rack -
set input values (client->body) when BODY_TYPE_BUFFER

kubo39/bossan,kubo39/bossan,kubo39/bossan