fix testcase bug: check and delete previous testcase if any testcases exit
fix testcase bug: before rejudge check previous testase exit or not ,yes: delete all old testcase record or skip deleting
fix testcase bug:befor rejudge check if any testcases of runid exit or not,
yes:delete all testace record
no: skip detele any record in database
fix testcase bug:befor rejudge check if any testcases of runid exit or not,
yes:delete all testace record
no: skip detele any record in database