fix latex code in one crystal file

[fchapoton]

and also notices a bug in the unicode art, fixed here.

The issue about latex was noticed in #38759

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[fchapoton]

The lines

ret.append(row[:-1] + vl)

in the unicode_art method are the main suspect for the wrong behaviour

[tscrim]

For the unicode art, the rows are just printed in reverse order it looks like since it displays to the left instead of to the right. So just reversing the rows when passed into the table fixes things (line 178):

-        table = [[None] * (self.cols - len(row)) + row for row in reversed(self)]
+        table = [[None] * (self.cols - len(row)) + list(reversed(row)) for row in reversed(self)]

So we can just fix it here if that's okay with you.

[fchapoton]

right, indeed, fixed.

[tscrim]

LGTM.