Fix column_table based mixer runs get_diff properly
Fix column_table based mixer runs get_diff properly

rimms/jubatus_core,kumagi/jubatus_core,kumagi/jubatus_core,rimms/jubatus_core,gintenlabo/jubatus_core,kumagi/jubatus_core,gintenlabo/jubatus_core,gintenlabo/jubatus_core,rimms/jubatus_core,rimms/jubatus_core,gintenlabo/jubatus_core,kumagi/jubatus_core