#389 ASan crash - linkdead character rejoining

need more protection in the LD code

    #1 0x555555f0e77e in Client::UpdateCharacterInstances() ../WorldServer/client.cpp:4231
    #2 0x555555f0e7f4 in Client::Save() ../WorldServer/client.cpp:4210
    #3 0x555555f0ea40 in Client::Disconnect(bool) ../WorldServer/client.cpp:3643
    #4 0x555555a057d7 in ZoneServer::ClientProcess() ../WorldServer/zoneserver.cpp:3217
    #5 0x555555a11d3f in ZoneServer::Process() ../WorldServer/zoneserver.cpp:1399
    #6 0x555555a1d4ba in ZoneLoop(void*) ../WorldServer/zoneserver.cpp:6875
    #7 0x7ffff6fbbfa2 in start_thread /build/glibc-vjB4T1/glibc-2.28/nptl/pthread_create.c:486
    #8 0x7ffff68264ce in clone (/lib/x86_64-linux-gnu/libc.so.6+0xf94ce)

0x61f00005b6b8 is located 1592 bytes inside of 2976-byte region [0x61f00005b080,0x61f00005bc20)
freed by thread T0 here:
    #0 0x7ffff72df128 in operator delete(void*, unsigned long) (/lib/x86_64-linux-gnu/libasan.so.5+0xec128)
    #1 0x555555aaf9ff in HandleDeletes<Client*>::CheckDeletes(bool) (/home/eq2emu_server/server/eq2world+0x55b9ff)
    #2 0x555555aaffb1 in MutexList<Client*>::update(bool) (/home/eq2emu_server/server/eq2world+0x55bfb1)
    #3 0x5555559a85e4 in MutexList<Client*>::Remove(Client*, bool, unsigned int) ../WorldServer/MutexList.h:203
    #4 0x5555559a85e4 in ZoneServer::RemoveClientImmediately(Client*) ../WorldServer/zoneserver.cpp:3159
    #5 0x555555f9bc34 in Client::HandleNewLogin(unsigned int, unsigned int) ../WorldServer/client.cpp:9837
    #6 0x555555fa030c in Client::HandlePacket(EQApplicationPacket*) ../WorldServer/client.cpp:1061
    #7 0x555555fc097c in Client::Process(bool) ../WorldServer/client.cpp:3002
    #8 0x555555fc3772 in ClientList::Process() ../WorldServer/client.cpp:3297
    #9 0x555555c6418e in main ../WorldServer/net.cpp:458
    #10 0x7ffff675109a in __libc_start_main ../csu/libc-start.c:308

our MutexLists are flawed and don't protect memory space.. connected_clients needs to be purged

This was resolved by fcc409dacc

when we removed the usage of: connected_clients.Remove(client, true);

connected_clients is now used in a limited fashion to transition the client from an initializing EQStream to a connected client (and client processing). It also handles the final deletion of memory when the client is completely purged.