Blueprint references to level Actors are lost when streaming out and back in the level

Hi,

Unfortunately this patch introduced another bug during level transitions in multiplayer. Game crashes with following callstack in FRepLayout.

FRepLayout::DestructProperties() [replayout.cpp:3539]
FRepChangelistState::~FRepChangelistState() [replayout.cpp:3598]
FReplicationChangelistMgr::~FReplicationChangelistMgr() [datareplication.cpp:359]
SharedPointerInternals::TReferenceControllerWithDeleter >::DestroyObject() [sharedpointerinternals.h:110]
TSet,TSharedPtr >,TDefaultMapHashableKeyFuncs,TSharedPtr,0>,FDefaultSetAllocator>::Remove() [set.h:614]
UNetDriver::TickFlush() [networkdriver.cpp:836]