dwarf-fortress: TWBT: use fork for dfhack 0.47.04 support
dwarf-fortress: TWBT: use fork for dfhack 0.47.04 support

The original mifki TWBT hasn't been updated since April 2019, while
thurin's fork has added support for dfhack 0.47.04-r2. Thus, switch to
thurin's fork when Dwarf Fortress 0.47.04 is used (and ever-so-slightly
special case the url attribute).

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