Fixes:
- the app closing after a new-mail sound - (#644)
- the app closing as a reply was sent after a sound with the Vulkan renderer - (#661)
- account settings hints left in English - (#656)
- Save as File and View Source doing nothing for a message opened from a file - (#398)
- addresses and handles in plain-text mail not being links - (#653)
- no contact groups from Nextcloud books - (#652)
- attachment icons in fixed colors that ignored the theme - (#651)
- the file previewer opening without focus on X11 - (#625)
Full changelog: v1.47.1...v1.48.1