Localize links to /donate (Closes: #14561).
We have recently hardcoded links to https://tails.boum.org/donate?r=contribute in the msgstr:s, so there are two cases: * Browser that prefers pages in some language that's not English: thankfully, we also have Apache language negotiation so even such hardcoded links result in the correct, localized page to be displayed in this case. * Browser that prefers pages in English (e.g. Tor Browser in Tails, Tor Browser configured to do so when first prompted): as you noticed, the English version of our donate page is always displayed. This commit fixes the second case by hardcoding links to the localized version of /donate.