Over-long msgstr not line wrapped when setting `--width`

[SlowMo24]

A .po file containing the following translation

msgid "Lorem Ipsum is"
msgstr "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industrystandard"

will not be line-wrapped with this command:

   pybabel update \
       -w 120 \
       -i messages.pot \
       -d .

even though the msgstr is >120 characters. The line will even get unwrapped if it was wrapped before like so:

msgstr ""
"Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industrystandard"

This behaviour can lead to vslavik/poedit#922.

This issue may be linked to #787 ?