Lists in EmailTemplate are incorrectly formatted

[brad2014]

Steps to reproduce

1. Perform an action that creates a server email containing a list, for example, create a calendar event with an invitee
2. Notice, in the invitee email, that the html list box is incorrectly formatted (in the source, you see width=100%% with two percent signs).

Note: listBegin in lib/private/Mail/EMailTemplate.php is used directly, not passed as an argument to vsprintf, so its percent symbols should not be escaped.

[nextcloud-bot]

GitMate.io thinks possibly related issues are #11544 (User list), #5607 (encryption compatible list ), #8312 (Specify Preview Format), #9005 (c), and #10442 (Contact list broken layout).