DataFormats/Common: edm::WrapperBase class version updated

This should fix the compilation errors in 7_3_DEVEL_X. @Dr15Jones, @ktf 

https://cmssdt.cern.ch/SDT/cgi-bin/buildlogs/slc6_amd64_gcc481/CMSSW_7_3_DEVEL_X_2014-10-13-1400/DataFormats/Common