Prevent Sympa daemon crash due to a broken plugin module.

[racke]

A mistake in a plugin module crashed sympa hard:

Nov 21 17:54:14 local-sympa sympa_msg[14599]: err main::#243 > Sympa::Spindle::spin#95 > Sympa::Spindle::TransformOutgoing::_twist#48 > Sympa::Message::Plugin::execute#61 > (eval)#1 > (eval)#1 > Sympa::Message::Plugin::BEGIN#1 DIED: Global symbol "$list" requires explicit package name (did you forget to declare "my $list"?) at /usr/local/lib/site_perl/Sympa/Plugin/DistributionNotification.pm line 24. Compilation failed in require at (eval 208) line 1.
Nov 21 17:54:14 local-sympa systemd[1]: sympa.service: Main process exited, code=exited, status=255/n/a
Nov 21 17:54:14 local-sympa systemd[1]: sympa.service: Unit entered failed state.
Nov 21 17:54:14 local-sympa systemd[1]: sympa.service: Failed with result 'exit-code'.

Justification for the introduction of the Module::Runtime dependency:

• does the right thing without head scratching and homegrown code
• small footprint

[ikedas]

Thanks!