Author: Ruslan Kabalin
MDL-50887 antivirus: Replace 'antiviruses' with 'antivirus plugins'.
Language string chnages as per Helen Foster's comments in the ticket.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=56e915bb82ff3e2ee48e4b37ff3b0e639f381c03
http://github.com/moodle/moodle/commit/56e915bb82ff3e2ee48e4b37ff3b0e639f381c03
+ 3.1 en [actantivirushdr,antivirus]
+ 3.1 en [antiviruses,antivirus]
+ 3.1 en [antivirussettings,antivirus]