sponsor-overview.html: fix small typo in html and .po files

Hello

I'm working currently on the German translation on https://hosted.weblate.org/translate/debexpo/debexpo.

I fixed a small typo in the English version but some jobs are failing and I don't know how I could fix that. Only trans, unstable and bookworm-bpo are affected.

See branch on my fork: https://salsa.debian.org/ahu/debexpo/-/tree/improvements

trans

processing locale pt_BR
processing locale fr
$ git checkout "*.po"
$ find debexpo -name '*.po' | while read po; do set -e; msgcmp --use-fuzzy --use-untranslated "${po}" "$(echo "${po}" | rev | cut -d / -f 4- | rev)/django.pot"; done
debexpo/base/locale/django.pot:968: this message is used but not defined...
debexpo/base/locale/fr/LC_MESSAGES/django.po:1320: ...but this definition is similar
msgcmp: found 1 fatal error
Cleaning up project directory and file based variables
ERROR: Job failed: exit code 1

Unstable and bookworm-bpo

Best match: PySimpleSOAP 1.16.2
Adding PySimpleSOAP 1.16.2 to easy-install.pth file

Using /usr/lib/python3/dist-packages
Finished processing dependencies for debexpo==3.0
$ (! grep Downloading /tmp/deps.txt)
Downloading https://files.pythonhosted.org/packages/e7/90/c5603098b224e190978f1d1842b12ec64e5f5295a8c117642ac1aa9793c7/python_debianbts-3.2.4-py3-none-any.whl#sha256=7a62796db848d7c47053b18d767620056f51c9bf221aca1fb7e094cb49b1e1e4
Cleaning up project directory and file based variables
ERROR: Job failed: exit code 1

Thanks a lot for some hints so I could prevent these job failings.

Cheers Andreas