To the leader of one of the state’s most prominent criminal justice reform groups, Gov. Bruce Rauner’s veto last week of Senate Bill 1830 was perplexing.The measure would have placed a variety of checks on the use of informants in certain criminal cases. Rauner said in a statement Friday those extra rules for informants aren’t needed because courts already have rules for admitting evidence and protecting against unreliable testimony.But those rules were also in place when the state wrongly sent 13 men to …