Fix Ukrainian translation

Fixes issue 6101
Update Brazilian Portuguese translation
Update French translation
Merge branch 'translations'
Add posteo.de to providers.xml

Add Posteo.de to providers.xml (according to https://autoconfig.thunderbird.net/v1.1/posteo.de and https://autoconfig.posteo.de/mail/config-v1.1.xml)
Add Azet.sk to providers.xml
Merge branch 'providers'
Merge remote-tracking branch 'upstream/master'