Fix ROOT-7007: make TFriendElment zombie when the tree does not exist
Fix ROOT-7007: make TFriendElment zombie when the tree does not exist

mkret2/root,Duraznos/root,mkret2/root,CristinaCristescu/root,georgtroska/root,Y--/root,nilqed/root,BerserkerTroll/root,esakellari/root,abhinavmoudgil95/root,krafczyk/root,olifre/root,zzxuanyuan/root-compressor-dummy,evgeny-boger/root,davidlt/root,Duraznos/root,pspe/root,pspe/root,georgtroska/root,zzxuanyuan/root-compressor-dummy,evgeny-boger/root,georgtroska/root,thomaskeck/root,jrtomps/root,davidlt/root,Duraznos/root,arch1tect0r/root,davidlt/root,karies/root,sirinath/root,veprbl/root,sawenzel/root,lgiommi/root,CristinaCristescu/root,krafczyk/root,georgtroska/root,thomaskeck/root,gganis/root,gbitzes/root,satyarth934/root,vukasinmilosevic/root,mattkretz/root,buuck/root,zzxuanyuan/root,gganis/root,vukasinmilosevic/root,arch1tect0r/root,veprbl/root,karies/root,mhuwiler/rootauto,agarciamontoro/root,olifre/root,Y--/root,esakellari/root,vukasinmilosevic/root,zzxuanyuan/root,georgtroska/root,simonpf/root,jrtomps/root,gbitzes/root,sirinath/root,jrtomps/root,arch1tect0r/root,nilqed/root,karies/root,bbockelm/root,sawenzel/root,nilqed/root,CristinaCristescu/root,mattkretz/root,root-mirror/root,abhinavmoudgil95/root,beniz/root,davidlt/root,arch1tect0r/root,buuck/root,gganis/root,sawenzel/root,abhinavmoudgil95/root,abhinavmoudgil95/root,nilqed/root,root-mirror/root,gbitzes/root,lgiommi/root,thomaskeck/root,lgiommi/root,buuck/root,arch1tect0r/root,lgiommi/root,root-mirror/root,buuck/root,vukasinmilosevic/root,sawenzel/root,thomaskeck/root,mhuwiler/rootauto,krafczyk/root,abhinavmoudgil95/root,arch1tect0r/root,mkret2/root,root-mirror/root,Duraznos/root,sirinath/root,beniz/root,bbockelm/root,nilqed/root,davidlt/root,CristinaCristescu/root,jrtomps/root,mkret2/root,lgiommi/root,jrtomps/root,buuck/root,mhuwiler/rootauto,olifre/root,karies/root,jrtomps/root,esakellari/root,nilqed/root,lgiommi/root,satyarth934/root,bbockelm/root,satyarth934/root,karies/root,Duraznos/root,sirinath/root,lgiommi/root,BerserkerTroll/root,sirinath/root,pspe/root,pspe/root,arch1tect0r/root,lgiommi/root,pspe/root,Y--/root,esakellari/root,omazapa/root,omazapa/root,vukasinmilosevic/root,pspe/root,sirinath/root,karies/root,davidlt/root,Duraznos/root,root-mirror/root,krafczyk/root,abhinavmoudgil95/root,veprbl/root,sirinath/root,gbitzes/root,sawenzel/root,bbockelm/root,thomaskeck/root,Duraznos/root,sawenzel/root,Duraznos/root,satyarth934/root,lgiommi/root,vukasinmilosevic/root,satyarth934/root,arch1tect0r/root,krafczyk/root,esakellari/root,omazapa/root,gbitzes/root,georgtroska/root,zzxuanyuan/root-compressor-dummy,sirinath/root,arch1tect0r/root,gganis/root,esakellari/root,omazapa/root,evgeny-boger/root,omazapa/root,zzxuanyuan/root-compressor-dummy,zzxuanyuan/root,pspe/root,zzxuanyuan/root,georgtroska/root,mattkretz/root,Y--/root,simonpf/root,nilqed/root,thomaskeck/root,simonpf/root,zzxuanyuan/root,sawenzel/root,zzxuanyuan/root-compressor-dummy,CristinaCristescu/root,nilqed/root,mattkretz/root,vukasinmilosevic/root,simonpf/root,vukasinmilosevic/root,omazapa/root,thomaskeck/root,mattkretz/root,mhuwiler/rootauto,karies/root,simonpf/root,perovic/root,zzxuanyuan/root-compressor-dummy,beniz/root,davidlt/root,mhuwiler/rootauto,vukasinmilosevic/root,veprbl/root,perovic/root,olifre/root,BerserkerTroll/root,lgiommi/root,mkret2/root,Y--/root,olifre/root,mkret2/root,georgtroska/root,gganis/root,perovic/root,veprbl/root,mattkretz/root,Y--/root,perovic/root,zzxuanyuan/root,veprbl/root,jrtomps/root,simonpf/root,buuck/root,gganis/root,georgtroska/root,karies/root,arch1tect0r/root,perovic/root,esakellari/root,pspe/root,olifre/root,simonpf/root,CristinaCristescu/root,perovic/root,bbockelm/root,Y--/root,beniz/root,buuck/root,zzxuanyuan/root,agarciamontoro/root,mattkretz/root,sirinath/root,zzxuanyuan/root,karies/root,satyarth934/root,CristinaCristescu/root,vukasinmilosevic/root,mkret2/root,beniz/root,gbitzes/root,simonpf/root,veprbl/root,lgiommi/root,veprbl/root,root-mirror/root,zzxuanyuan/root,agarciamontoro/root,thomaskeck/root,sawenzel/root,bbockelm/root,zzxuanyuan/root-compressor-dummy,zzxuanyuan/root-compressor-dummy,omazapa/root,simonpf/root,root-mirror/root,krafczyk/root,krafczyk/root,agarciamontoro/root,zzxuanyuan/root-compressor-dummy,sawenzel/root,root-mirror/root,olifre/root,esakellari/root,agarciamontoro/root,satyarth934/root,sirinath/root,georgtroska/root,veprbl/root,bbockelm/root,gganis/root,abhinavmoudgil95/root,Y--/root,gganis/root,vukasinmilosevic/root,davidlt/root,BerserkerTroll/root,krafczyk/root,Duraznos/root,Y--/root,abhinavmoudgil95/root,mkret2/root,evgeny-boger/root,sawenzel/root,agarciamontoro/root,zzxuanyuan/root,pspe/root,omazapa/root,perovic/root,mhuwiler/rootauto,omazapa/root,perovic/root,jrtomps/root,mattkretz/root,bbockelm/root,BerserkerTroll/root,gganis/root,omazapa/root,BerserkerTroll/root,mhuwiler/rootauto,satyarth934/root,gbitzes/root,mkret2/root,satyarth934/root,mattkretz/root,karies/root,krafczyk/root,root-mirror/root,davidlt/root,gganis/root,olifre/root,agarciamontoro/root,mattkretz/root,beniz/root,thomaskeck/root,agarciamontoro/root,mattkretz/root,BerserkerTroll/root,beniz/root,krafczyk/root,esakellari/root,gganis/root,CristinaCristescu/root,mkret2/root,pspe/root,BerserkerTroll/root,root-mirror/root,buuck/root,satyarth934/root,buuck/root,arch1tect0r/root,simonpf/root,zzxuanyuan/root,beniz/root,evgeny-boger/root,olifre/root,olifre/root,jrtomps/root,karies/root,agarciamontoro/root,mkret2/root,BerserkerTroll/root,omazapa/root,beniz/root,zzxuanyuan/root-compressor-dummy,beniz/root,perovic/root,thomaskeck/root,CristinaCristescu/root,jrtomps/root,gbitzes/root,satyarth934/root,BerserkerTroll/root,Duraznos/root,nilqed/root,abhinavmoudgil95/root,beniz/root,abhinavmoudgil95/root,nilqed/root,abhinavmoudgil95/root,sirinath/root,simonpf/root,gbitzes/root,Duraznos/root,esakellari/root,root-mirror/root,georgtroska/root,davidlt/root,gbitzes/root,buuck/root,agarciamontoro/root,CristinaCristescu/root,bbockelm/root,agarciamontoro/root,perovic/root,veprbl/root,mhuwiler/rootauto,CristinaCristescu/root,esakellari/root,mhuwiler/rootauto,evgeny-boger/root,evgeny-boger/root,olifre/root,perovic/root,evgeny-boger/root,evgeny-boger/root,BerserkerTroll/root,davidlt/root,krafczyk/root,nilqed/root,bbockelm/root,evgeny-boger/root,gbitzes/root,evgeny-boger/root,jrtomps/root,zzxuanyuan/root-compressor-dummy,Y--/root,Y--/root,buuck/root,pspe/root,mhuwiler/rootauto,mhuwiler/rootauto,zzxuanyuan/root,bbockelm/root,veprbl/root,sawenzel/root