add spaces to stacktrace in exception
add spaces to stacktrace in exception

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