made grammar functional again after it was made significantly worse and then crashed

psGrammar/confirm/confirm.jsgf

@@ -7,4 +7,4 @@ public <confirm> = <confirm_yes> | <confirm_no>;
 
 <yes_words> = (yes);
 <no_words> = (no);
-<robot> = (tiago, tobi);
+<robot> = (tiago)| (tobi) | (robot);