package/exim: security bump to version 4.92.2
Fixes CVE-2019-15846: Local or remote attacker can execute programs with
root privileges
For details, see the advisory:
https://exim.org/static/doc/security/CVE-2019-15846.txt
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>