Arabic transliteration module incompatible with Lua ≥5.2

[skalyan91]

In line 332 of wikt/translit/ar-translit.lua, unpack(sub) should be replaced with table.unpack(sub), otherwise Lua throws the error attempt to call a nil value (global 'unpack').

This may also be an issue with other transliteration modules, but I have not checked if there are any others that use unpack.