change config and repaired confirm grammar

psConfig/exercise/team2/team2.conf

 [main]
-startdb=50;
-uttdb=55;
+startdb=45;
+uttdb=49;
 silence=400;
 timeout=8;
 openDeviceDirectly=yes;

psGrammar/exercise/team2/confirm.jsgf

@@ -2,9 +2,9 @@
 grammar ToBI_confirm;
 public <confirm> = <confirm_yes> | <confirm_no>;
 
-<confirm_yes> = <robot> <yes_words>;
-<confirm_no> = <robot> <no_words>; 
+<confirm_yes> = [<robot>] <yes_words>;
+<confirm_no> = [<robot>] <no_words>; 
 
 <yes_words> = (yes) | (confirmed);
 <no_words> = (no);
-<robot> = (tobi) | (robot) | (biron) | (pepper);
+<robot> = (tobi) | (robot) | (biron) | (pepper) | (meka);