nextcloud 12 changing emails on users?

[alexweirig]

After we installed nextcloud 12 in test (upgrade from 11.0.3) some users complain about getting the following emails:
Email address changed for Nadine Gaasch
Owncloud Admin changed your email address on https://nextcloud.technolink.lu:8443/. If you did not request this, please contact an administrator.
The new email address is muriel.achour@technolink.lu

Steps to reproduce

1. installed nc 12 upgrade from 11.0.3
2. users complain

Expected behaviour

emails should not be changed

Actual behaviour

not sure what is happening ... emails are not changed in LDAP

same configuration as in #5168

[nickvergessen]

Fix is in https://github.com/nextcloud/server/pull/5126/files
And will come with 12.0.1