#249 stacked flag is updated too late

[Jens Granseuer]

I have a character with no unused inventory slots. One of those lots contains a stackable item with less than MaxStackAmount copies. With another character I find another copy of this item in a container. I pick it up and, without putting it in that character's inventory first, pass it on to the first character. The handover fails because GemRB thinks the items are not compatible due to the missing STACKED flag on the newly found item. (see Inventory::ItemsAreCompatible)

[Jens Granseuer]

update flag earlier

[Jaka Kranjc]

It's in, thanks.