i18n tweak for article reminder category on preferences
i18n tweak for article reminder category on preferences

Due to team discussion - there is a need to keep the singular-plural

This makes it consistent with the others and allows flexibility.

Change-Id: I990a09cc688dcdae3176c5ecd995d4957a4bc402

wikimedia/mediawiki-extensions-Echo,wikimedia/mediawiki-extensions-Echo,wikimedia/mediawiki-extensions-Echo,wikimedia/mediawiki-extensions-Echo