21.1.20210629

• Mail/Admin: fix not working mail wizard
• Mail/SMIME: fix signed calendar events not being displayed (error:importing the ical!)
• Mail/Dovecot: allow to disable caching of flags in site config to support Dovecot private seen flags on shared folders
• Api: Prevent invalid customfield names
• Api: Clear initial load URL after using it, so F5 takes you to the app's normal entry point
• InfoLog: allow to limit list to last N month in site-configuration, if ordered by last modified
• Setup: skip files backup on update even if configured
• smallPART: only show own memberships when selecting an organisation for a course
• smallPART: allow to create new courses via LTI content-selection
• Extended changelog