StringUtils: Fixed bad predicate in MergeStringVectors().
StringUtils: Fixed bad predicate in MergeStringVectors().

Instead of preventing duplicates it was allowing only duplicates.

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