Still need to loop again when EAGAIN after a read triggered by an event, Fixes #363

Fixes #363
After a read event gets triggered and we try to read the body, sometimes the frontend might send it in chunks and there won't be the whole body in there, after a second read(proto_read_body might do several socket reads) EAGAINS the logical step is to wait again for a read event as the frontend will be sending the rest of the body soon.