/etc/quotagrpadmins is in quota 4.01-8+deb8u1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 | #
# This is a sample groupadmins file (/etc/quotagrpadmins)
#
# Comments begin with hash in the beginning of the line
# In this file you specify users responsible for space used by the group
users: root
mygroup: chief
|