Log Message:
Update to 52.3.0

Changelog:
    Fixed
    Unwanted inline images shown in rogue SPAM messages

    Fixed
    Deleting message from the POP3 server not working when maildir storage was used

    Fixed
    Message disposition flag (replied / forwarded) lost when reply or forwarded \ 
message was stored as draft and draft was sent later

    Fixed
    Inline images not scaled to fit when printing

    Fixed
    Selected text from another message sometimes included in a reply

    Fixed
    No authorisation prompt displayed when inserting image into email body \ 
although image URL requires authentication

    Fixed
    Large attachments taking a long time to open under some circumstances

    Fixed
    Various security fixes