Fixed a typo in depot tile

[omarcopires]

Pull Request Prelude

• I have followed proper The Forgotten Server code styling.
• I have read and understood the contribution guidelines before making this PR.
• I am aware that this PR may be closed if the above-mentioned criteria are not fulfilled.

[MillhioreBT]

you have 0 item. mmm
you have 0 items. it makes more sense.
I don't know much about English grammar so let's hope someone who does check it out.

[Zbizu]

Articles a/an in English mean one. We can say "there is one item". When there are zero items, we say "there are no items".

There's an article on BBC site explaining it with details for uncountables also, but it doesn't cite anything:
https://www.bbc.co.uk/worldservice/learningenglish/grammar/learnit/learnitv354.shtml