Fix issue that can cause Shutdown() to hang
Fix issue that can cause Shutdown() to hang

dgnorton/raft,hashicorp/raft,tempbottle/raft-2,PattyW/raft_govec,otoolep/raft,wantonsolutions/raft,quantiply-fork/raft,hashicorp/raft,jmptrader/raft-1,sean-/raft