Merge branch '5687-use-of-uninitialized-value-in-concatenation-or-string-at-usr-share-perl5-argonaut-server-modules-opsi-pm-line-309' into 'argonaut-1.3-dev'

Resolve "Use of uninitialized value in concatenation (.) or string at /usr/share/perl5/Argonaut/Server/Modules/OPSI.pm line 309."

Closes #5687

See merge request !14

(cherry picked from commit 095bd3a4)

96508409 🚑 fix(server-module-opsi): Fix perl error