fix shop ownership of saddle dropped by dead pet (trunk only)

fix shop ownership of saddle dropped by dead pet (trunk only)

     From a bug report, you could obtain
a saddle for free if it was dropped (while worn) by a dying pet inside a
shop.  That's intentional, but it was happening even when the hero was
not in the shop, which doesn't seem right.  Change things to only set it
no_charge if hero is within the same shop (including standing in the
doorway or a temporary wall breach, not just when all the way inside) at
the time of the drop.