Last modified: 2012-07-31 19:51:51 UTC
Message Maintenance-cleanupTable-finished should support PLURAL for parameters $2 and $3. See http://www.mediawiki.org/wiki/Localisation#Be_aware_of_PLURAL_use_on_all_numbers for some more background information.
Source: http://translatewiki.net/wiki/Thread:Support/MediaWiki:Maintenance-cleanupTable-finished/en
Not related to core maintenance scripts, moving bug.
Fixed in Gerrit change #16931.