Fix so scheduler doesn't die when a thread raises exception
Fix so scheduler doesn't die when a thread raises exception

Missing return statement made scheduler die when a thread raised an exception.

VamsikrishnaNallabothu/pox,kpengboy/pox-exercise,waltznetworks/pox,chenyuntc/pox,chenyuntc/pox,VamsikrishnaNallabothu/pox,pthien92/sdn,carlye566/IoT-POX,jacobq/csci5221-viro-project,noxrepo/pox,andiwundsam/_of_normalize,kavitshah8/SDNDeveloper,waltznetworks/pox,diogommartins/pox,pthien92/sdn,andiwundsam/_of_normalize,chenyuntc/pox,diogommartins/pox,kavitshah8/SDNDeveloper,jacobq/csci5221-viro-project,MurphyMc/pox,adusia/pox,denovogroup/pox,kpengboy/pox-exercise,MurphyMc/pox,pthien92/sdn,andiwundsam/_of_normalize,kpengboy/pox-exercise,kpengboy/pox-exercise,noxrepo/pox,jacobq/csci5221-viro-project,PrincetonUniversity/pox,denovogroup/pox,kulawczukmarcin/mypox,xAKLx/pox,kavitshah8/SDNDeveloper,xAKLx/pox,xAKLx/pox,carlye566/IoT-POX,kulawczukmarcin/mypox,VamsikrishnaNallabothu/pox,carlye566/IoT-POX,denovogroup/pox,pthien92/sdn,noxrepo/pox,PrincetonUniversity/pox,diogommartins/pox,jacobq/csci5221-viro-project,adusia/pox,kulawczukmarcin/mypox,kpengboy/pox-exercise,PrincetonUniversity/pox,kulawczukmarcin/mypox,xAKLx/pox,kavitshah8/SDNDeveloper,xAKLx/pox,denovogroup/pox,denovogroup/pox,pthien92/sdn,MurphyMc/pox,adusia/pox,kulawczukmarcin/mypox,diogommartins/pox,VamsikrishnaNallabothu/pox,carlye566/IoT-POX,waltznetworks/pox,PrincetonUniversity/pox,andiwundsam/_of_normalize,PrincetonUniversity/pox,chenyuntc/pox,adusia/pox,waltznetworks/pox,MurphyMc/pox,carlye566/IoT-POX,adusia/pox,noxrepo/pox,diogommartins/pox,VamsikrishnaNallabothu/pox,chenyuntc/pox,waltznetworks/pox,jacobq/csci5221-viro-project,MurphyMc/pox