Def unload: Fix overloaded function refcount

src/script/C4ScriptHost.cpp

@@ -99,7 +99,7 @@ void C4ScriptHost::UnlinkOwnedFunctions()
 				// Unlink the removed function from the inheritance chain
 				if (func_chain->OwnerOverloaded == func)
 				{
-					func_chain->OwnerOverloaded = func->OwnerOverloaded;
+					func_chain->SetOverloaded(func->OwnerOverloaded);
 					break;
 				}
 				assert(func_chain->OwnerOverloaded && "Removed function not found in inheritance chain");