src: svr-tcpfwd: Fix noremotetcp behavior

If noremotetcp is set, we should still reply with
send_msg_request_failed. This matches the behavior
of !DROPBEAR_SVR_REMOTETCPFWD.

We were seeing keepalive packets being ignored when
the "-k" option was used.

src/svr-tcpfwd.c

@@ -79,14 +79,14 @@ void recv_msg_global_request_remotetcp() {
 
 	TRACE(("enter recv_msg_global_request_remotetcp"))
 
+	reqname = buf_getstring(ses.payload, &namelen);
+	wantreply = buf_getbool(ses.payload);
+
 	if (svr_opts.noremotetcp || !svr_pubkey_allows_tcpfwd()) {
 		TRACE(("leave recv_msg_global_request_remotetcp: remote tcp forwarding disabled"))
 		goto out;
 	}
 
-	reqname = buf_getstring(ses.payload, &namelen);
-	wantreply = buf_getbool(ses.payload);
-
 	if (namelen > MAX_NAME_LEN) {
 		TRACE(("name len is wrong: %d", namelen))
 		goto out;