Export fails with UnicodeEncodeError

Hello Launchpad administrators,

Launchpad encountered problems exporting translation files
requested by compr00t (patrick-p-schmid) at

  https://translations.launchpad.net/ubuntu-manual/main/+export

This means we have a bug in Launchpad that needs to be fixed
before this export can proceed. Here is the error we got:

Traceback (most recent call last):
  File "/srv/launchpad.net/production/launchpad-rev-8806/lib/lp/translations/scripts/po_export_queue.py", line 338, in process_request
    generate_translationfiledata(list(objects), format))
  File "/srv/launchpad.net/production/launchpad-rev-8806/lib/lp/translations/utilities/gettext_po_exporter.py", line 315, in exportTranslationFiles
    chunks = [self._makeExportedHeader(translation_file)]
  File "/srv/launchpad.net/production/launchpad-rev-8806/lib/lp/translations/utilities/gettext_po_exporter.py", line 430, in _makeExportedHeader
    return exported_header.encode(charset)
UnicodeEncodeError: 'ascii' codec can't encode character u'\xe1' in position 402: ordinal not in range(128)

Failed export request included:
  * ubuntu-manual in Ubuntu Manual main
  * Serbian (sr) translation of ubuntu-manual in Ubuntu Manual main
  * Arabic (ar) translation of ubuntu-manual in Ubuntu Manual main
  * Korean (ko) translation of ubuntu-manual in Ubuntu Manual main
  * Catalan (ca) translation of ubuntu-manual in Ubuntu Manual main
  * Spanish (es) translation of ubuntu-manual in Ubuntu Manual main
  * Dutch (nl) translation of ubuntu-manual in Ubuntu Manual main
  * Galician (gl) translation of ubuntu-manual in Ubuntu Manual main
  * Hindi (hi) translation of ubuntu-manual in Ubuntu Manual main
  * Portuguese (pt) translation of ubuntu-manual in Ubuntu Manual main
  * Norwegian Bokmal (nb) translation of ubuntu-manual in Ubuntu Manual main
  * Italian (it) translation of ubuntu-manual in Ubuntu Manual main
  * Polish (pl) translation of ubuntu-manual in Ubuntu Manual main
  * Czech (cs) translation of ubuntu-manual in Ubuntu Manual main
  * Chinese (Simplified) (zh_CN) translation of ubuntu-manual in Ubuntu Manual main
  * Asturian (ast) translation of ubuntu-manual in Ubuntu Manual main
  * Occitan (post 1500) (oc) translation of ubuntu-manual in Ubuntu Manual main
  * Latin (la) translation of ubuntu-manual in Ubuntu Manual main
  * Brazilian Portuguese (pt_BR) translation of ubuntu-manual in Ubuntu Manual main
  * Romanian (ro) translation of ubuntu-manual in Ubuntu Manual main
  * Russian (ru) translation of ubuntu-manual in Ubuntu Manual main
  * Greek, Ancient (to 1453) (grc) translation of ubuntu-manual in Ubuntu Manual main
  * Indonesian (id) translation of ubuntu-manual in Ubuntu Manual main
  * Persian (fa) translation of ubuntu-manual in Ubuntu Manual main
  * Japanese (ja) translation of ubuntu-manual in Ubuntu Manual main
  * Danish (da) translation of ubuntu-manual in Ubuntu Manual main
  * English (United Kingdom) (en_GB) translation of ubuntu-manual in Ubuntu Manual main
  * Lithuanian (lt) translation of ubuntu-manual in Ubuntu Manual main
  * German (de) translation of ubuntu-manual in Ubuntu Manual main
  * French (fr) translation of ubuntu-manual in Ubuntu Manual main