Fixed #3835 Delete MailBackup not working - Log shows a warning about SQL I...

Till Brehm

2016-04-20 86853d4d0fd66c277746e9e0cf07fbecbfbbc362

1
ALTER TABLE `shell_user` CHANGE `ssh_rsa` `ssh_rsa` TEXT CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL;