Update .gitattributes for .resx to merge=union
Update .gitattributes for .resx to merge=union

LianwMS/WebApi,lewischeng-ms/WebApi,congysu/WebApi,scz2011/WebApi,chimpinano/WebApi,LianwMS/WebApi,abkmr/WebApi,yonglehou/WebApi,yonglehou/WebApi,lungisam/WebApi,abkmr/WebApi,chimpinano/WebApi,scz2011/WebApi,lungisam/WebApi,lewischeng-ms/WebApi,congysu/WebApi