Codechange: do not use MallocT for the pool

Needed to make the placement new operator use Tindex over size_t because of
ambiguity for the delete operator variant that also has the size.

src/saveload/depot_sl.cpp

@@ -49,7 +49,7 @@ struct DEPTChunkHandler : ChunkHandler {
 		int index;
 
 		while ((index = SlIterateArray()) != -1) {
-			Depot *depot = new (index) Depot();
+			Depot *depot = new (DepotID(index)) Depot();
 			SlObject(depot, slt);
 
 			/* Set the town 'pointer' so we can restore it later. */