Add Null check to SendBlockTo
Add Null check to SendBlockTo

Fixes CID 43611
johnsoch/cuberite,SamOatesPlugins/cuberite,marvinkopf/cuberite,Howaner/MCServer,Fighter19/cuberite,kevinr/cuberite,thetaeo/cuberite,guijun/MCServer,ionux/MCServer,Howaner/MCServer,johnsoch/cuberite,zackp30/cuberite,Haxi52/cuberite,guijun/MCServer,HelenaKitty/EbooMC,SamOatesPlugins/cuberite,Frownigami1/cuberite,marvinkopf/cuberite,nevercast/cuberite,Haxi52/cuberite,Howaner/MCServer,Haxi52/cuberite,linnemannr/MCServer,Schwertspize/cuberite,ionux/MCServer,Frownigami1/cuberite,mjssw/cuberite,Howaner/MCServer,birkett/MCServer,mc-server/MCServer,tonibm19/cuberite,thetaeo/cuberite,ionux/MCServer,electromatter/cuberite,Fighter19/cuberite,Schwertspize/cuberite,nicodinh/cuberite,birkett/cuberite,nichwall/cuberite,Howaner/MCServer,nounoursheureux/MCServer,linnemannr/MCServer,electromatter/cuberite,johnsoch/cuberite,birkett/MCServer,linnemannr/MCServer,nevercast/cuberite,SamOatesPlugins/cuberite,Altenius/cuberite,Altenius/cuberite,thetaeo/cuberite,bendl/cuberite,ionux/MCServer,marvinkopf/cuberite,nevercast/cuberite,Altenius/cuberite,birkett/MCServer,mmdk95/cuberite,kevinr/cuberite,Haxi52/cuberite,mjssw/cuberite,nichwall/cuberite,linnemannr/MCServer,birkett/cuberite,nichwall/cuberite,Schwertspize/cuberite,nevercast/cuberite,linnemannr/MCServer,mjssw/cuberite,birkett/cuberite,birkett/MCServer,marvinkopf/cuberite,QUSpilPrgm/cuberite,nicodinh/cuberite,tonibm19/cuberite,thetaeo/cuberite,nounoursheureux/MCServer,tonibm19/cuberite,QUSpilPrgm/cuberite,Fighter19/cuberite,Howaner/MCServer,bendl/cuberite,HelenaKitty/EbooMC,mmdk95/cuberite,zackp30/cuberite,mc-server/MCServer,ionux/MCServer,HelenaKitty/EbooMC,marvinkopf/cuberite,electromatter/cuberite,kevinr/cuberite,Altenius/cuberite,QUSpilPrgm/cuberite,birkett/MCServer,Tri125/MCServer,kevinr/cuberite,birkett/cuberite,Frownigami1/cuberite,tonibm19/cuberite,thetaeo/cuberite,Frownigami1/cuberite,nounoursheureux/MCServer,jammet/MCServer,Haxi52/cuberite,mjssw/cuberite,tonibm19/cuberite,zackp30/cuberite,HelenaKitty/EbooMC,guijun/MCServer,Fighter19/cuberite,nicodinh/cuberite,QUSpilPrgm/cuberite,nicodinh/cuberite,bendl/cuberite,birkett/cuberite,mc-server/MCServer,Frownigami1/cuberite,Tri125/MCServer,Schwertspize/cuberite,Fighter19/cuberite,nounoursheureux/MCServer,guijun/MCServer,electromatter/cuberite,jammet/MCServer,guijun/MCServer,mjssw/cuberite,nounoursheureux/MCServer,mc-server/MCServer,jammet/MCServer,nicodinh/cuberite,nounoursheureux/MCServer,johnsoch/cuberite,HelenaKitty/EbooMC,birkett/cuberite,johnsoch/cuberite,zackp30/cuberite,nicodinh/cuberite,linnemannr/MCServer,marvinkopf/cuberite,mmdk95/cuberite,jammet/MCServer,mc-server/MCServer,Schwertspize/cuberite,zackp30/cuberite,nichwall/cuberite,mjssw/cuberite,SamOatesPlugins/cuberite,guijun/MCServer,bendl/cuberite,jammet/MCServer,QUSpilPrgm/cuberite,ionux/MCServer,kevinr/cuberite,nevercast/cuberite,mc-server/MCServer,mmdk95/cuberite,tonibm19/cuberite,mmdk95/cuberite,birkett/MCServer,Altenius/cuberite,Haxi52/cuberite,Tri125/MCServer,Fighter19/cuberite,SamOatesPlugins/cuberite,electromatter/cuberite,electromatter/cuberite,Tri125/MCServer,kevinr/cuberite,nevercast/cuberite,QUSpilPrgm/cuberite,zackp30/cuberite,nichwall/cuberite,bendl/cuberite,jammet/MCServer,thetaeo/cuberite,mmdk95/cuberite,nichwall/cuberite,Tri125/MCServer,Tri125/MCServer