Remove superfluous check for "skip", it's already done previous in the loop

mysql-test/lib/mtr_cases.pl

@@ -484,7 +484,6 @@ sub optimize_cases {
       # w/o --mysqld=--binlog-format=xxx and combinations.
       # =======================================================
       if (!defined $tinfo->{'combination'} and
-          $tinfo->{'skip'} ne 1 and 
           !defined $::used_binlog_format)
       {
         $test_binlog_format= $tinfo->{'sup_binlog_formats'}->[0];