Custom logo-mail.gif in the notification email sometimes is owncloud logo

[cscherm]

Hi wildwebmaster,

you hit a known issue in ownCloud 10.6: https://doc.owncloud.com/server/admin_manual/release_notes.html#known-issues

Please do the following to patch your instance:

1. in your ownCloud directory execute wget https://github.com/owncloud/core/pull/38246.patch
2. execute patch -p1 < 38246.patch
3. done