Switch from deprecated GaudiKernel/Counters.h to Gaudi/Accumulators.h
Fixes warning
/usera/jonesc/LHCbCMake/Feature/Gaudi/InstallArea/x86_64-centos7-clang8-opt/include/GaudiKernel/Counters.h:13:11: warning: warning: deprecated header, use <Gaudi/Accumulators.h> instead [-W#pragma-messages]
# pragma message "warning: deprecated header, use <Gaudi/Accumulators.h> instead"
^
1 warning generated.
Edited by Rosen Matev