The bare CR is treated as CRLF on PETSCII, so use Ctrl-A[ instead

We don't do output translation for PETSCII terminals for CR or LF
chars, so this trick is needed, at least currently, for the NN legacy prompt
to be properly over-written/invisible for CBM/PETSCII terminals.

exec/login.js

@@ -34,8 +34,8 @@ for(var c=0; c < options.login_prompts; c++) {
 	bbs.nodesync();
 
 	// Display login prompt
-	const legacy_login_prompt = "NN: \r";
-	const legacy_password_prompt = "PW: \r";
+	const legacy_login_prompt = "NN: \x01[";
+	const legacy_password_prompt = "PW: \x01[";
 	var str = "\1n\1h\1cEnter \1wUser Name";
 	if(!(bbs.node_settings&NM_NO_NUM))
 		str += "\1c or \1wNumber";