Warn in release notes that internal groups can't contain external groups

Since the abstraction of the group system into the GroupBackend
interface, it is not possible anymore to have external groups as
members of internal groups. Add a warning about this to the Gerrit 2.5
release notes.

Change-Id: I076201d07b67bb63893f553169268d543ebf0a1d
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>
1 file changed