[crash] server crashes when trying to use old bestiary

[ronoaldo]

How to reproduce:

• Using previous draconis mod version, place some pages on the bestiary
• Update to 1.2
• Try to use the bestiary

For the update, perhaps consider replacing the old bestiary item with the new one? Not sure if this is possible actually.

[ronoaldo]

Logs (may be out of order 😬)

2022-02-19 19:12:27: ERROR[Main]: stack traceback:
2022-02-19 19:12:27: ERROR[Main]: ServerError: AsyncErr: ServerThread::run Lua: Runtime error from mod 'draconis' in callback item_OnPlace(): /usr/share/minetest/mods/draconis/items.lua:1215: attempt to index local 'pages' (a nil value)
2022-02-19 19:12:27: ERROR[Main]: /usr/share/minetest/mods/draconis/items.lua:1250: in function </usr/share/minetest/mods/draconis/items.lua:1240>
2022-02-19 19:12:27: ERROR[Main]: /usr/share/minetest/mods/draconis/items.lua:1215: in function 'libri_formspec'

[ElCeejo]

The old bestiary item is replaced via aliasing, but it seems like aliased items don't clear metadata for some reason.

[ElCeejo]

Fixed as of latest commit.