[ui][registration][templates] update mail account revalidation message

Fixes #570

Part of #558
1 job for 570_fix_url_prefix_usage_yearly_account_revalidation in 15 minutes and 59 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Build
passed #210111
docker-build
build_linux_36

00:15:59

69.0%