TrigP1Test: Fix dry run result in timeout test
This is a bugfix which fixes the unit test failure:
http://atlas-computing.web.cern.ch/atlas-computing/links/distDirectory/gitwww/GITWebArea/nightlies/master/2019-12-19T2131/Athena/x86_64-centos7-gcc8-opt/Athena/UT/TrigP1Test.log.html