Bug 14951: Remove C4::Dates from plugins/*.pl files

Bug 14951: Remove C4::Dates from plugins/*.pl files

This patch removes C4::Dates from:

- plugins/plugins-home.pl
- plugins/run.pl

C4::Dates seem not to be used here, removed.

For testing refer to:
http://manual.koha-community.org/3.20/en/pluginsystem.html
http://manual.koha-community.org/3.20/en/pluginsystem.html

Signed-off-by: Joonas Kylmälä <j.kylmala@gmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>