Update to version 3.9.3
New in this release:
* The TAB address completion in the Compose window now matches any
part of the address and not just the beginning.
* When copying or moving a message, the type-ahead search now matches
any part of a folder name and not just the beginning.
* It is now possible to replace the current signature in the Compose
window by using the '/Message/Replace signature' menu item.
* It is now possible to disable the 'Subject is empty' warning(Only the first 15 lines of the commit message are shown above )