[MDB] Images of diffs aren't being generated

[Raeschen]

I tested this on two different repos. The diff generates, but images (including raw links) are invalid.

All of Old - New - Diff, both the in-github preview and the raw link.

[AffectedArc07]

Link a PR please. Theres a chance this happened during me testing something,

[Raeschen]

a few:
CHOMPStation2/CHOMPStation2#6570
CHOMPStation2/CHOMPStation2#6568
CHOMPStation2/CHOMPStation2#6556

seems to of started happening very recently, past 2 days or so.

[Raeschen]

Additionally, as visible in this check;
https://github.com/CHOMPStation2/CHOMPStation2/pull/6570/checks?check_run_id=15038956772

One mapcheck failed, despite me fixing this error. And then, all of the diff generations after that have been shifted up.
For example, the image content of 'cabinisland' is actually shown in 'southern-cross-8', illustrated below;

[S34NW]

Happening on paradise also, see:
https://github.com/ParadiseSS13/Paradise/pull/21425/checks?check_run_id=15094584119
https://github.com/ParadiseSS13/Paradise/pull/21264/checks?check_run_id=15094576248
https://github.com/ParadiseSS13/Paradise/pull/21424/checks?check_run_id=15099542936

[Aquizit]

Yogs, too
https://github.com/yogstation13/Yogstation/pull/19646/checks?check_run_id=15003382492

[AffectedArc07]

CC @jupyterkat