Delete unnecessary virtual: fix #354
Delete unnecessary virtual: fix #354

roselleebarle04/jubatus,kmaehashi/jubatus,kumagi/jubatus_core,kmaehashi/jubatus_core,kumagi/jubatus_core,kmaehashi/jubatus,mathn/jubatus,Asuka52/jubatus,kmaehashi/jubatus_core,mathn/jubatus,gintenlabo/jubatus_core,gintenlabo/jubatus_core,rimms/jubatus_core,rimms/jubatus_core,jubatus/jubatus,rimms/jubatus,rimms/jubatus_core,jubatus/jubatus,kmaehashi/jubatus_core,jubatus/jubatus,elkingtonmcb/jubatus,kmaehashi/jubatus_core,rimms/jubatus_core,gintenlabo/jubatus,kumagi/jubatus_core,gintenlabo/jubatus_core,gintenlabo/jubatus,gintenlabo/jubatus_core,kumagi/jubatus_core,Asuka52/jubatus,elkingtonmcb/jubatus,rimms/jubatus,roselleebarle04/jubatus