tls: don't close connection on SSL_ERROR_ZERO_RETURN error (#217)

Author: richaas

src/tls/openssl/tls_tcp.c

@@ -306,13 +306,10 @@ static bool recv_handler(int *err, struct mbuf *mb, bool *estab, void *arg)
 
 			switch (ssl_err) {
 
+			case SSL_ERROR_ZERO_RETURN:
 			case SSL_ERROR_WANT_READ:
 				break;
 
-			case SSL_ERROR_ZERO_RETURN:
-				*err = ECONNRESET;
-				return true;
-
 			default:
 				*err = EPROTO;
 				return true;