exim script warns of uninitialized value $SelfSigned

[Frans de Vries]

Description: Ubuntu 22.04.1 LTS
Release: 22.04

logwatch:
  Installed: 7.5.6-1ubuntu1
  Candidate: 7.5.6-1ubuntu1
  Version table:
 *** 7.5.6-1ubuntu1 500
        500 http://us.archive.ubuntu.com/ubuntu jammy/main amd64 Packages
        100 /var/lib/dpkg/status

The mailed report contains this section:

 --------------------- EXIM Begin ------------------------

 Use of uninitialized value $SelfSigned in concatenation (.) or string at /usr/share/logwatch/scripts/services/exim line 334, <STDIN> line 434.

 --- Self-Signed Certificate in use ( Time(s))

 ---------------------- EXIM End -------------------------

I suspect this relates to line 98 which does a push, without incrementing $SelfSigned (like it does on line 275). Or simpler: the variable should be set to 0 at the start.