bug#43127: 27.1; gnus-use-correct-string-widths is still documented in the Gnus Info manual

[Daniel Martín]

Evaluate the following form in the scratch buffer:

(info "(gnus) Wide characters")

The documentation for this topic says "To help fix this, you can set
‘gnus-use-correct-string-widths’ to ‘t’"; however, the
'gnus-use-correct-string-widths' variable is not available anymore.

If an alternative way to achieve what's described in the manual is
available, it should be documented instead; if not, the whole section
should be removed to avoid confusion.