Updated language files and removed unused string:

plugins/CoreUpdater/lang/am.json

plugins/CoreUpdater/lang/ar.json

plugins/CoreUpdater/lang/be.json

plugins/CoreUpdater/lang/bg.json

plugins/CoreUpdater/lang/ca.json

plugins/CoreUpdater/lang/cs.json

plugins/CoreUpdater/lang/da.json

plugins/CoreUpdater/lang/de.json

plugins/CoreUpdater/lang/el.json

plugins/CoreUpdater/lang/es.json

plugins/CoreUpdater/lang/et.json

plugins/CoreUpdater/lang/eu.json

plugins/CoreUpdater/lang/fa.json

plugins/CoreUpdater/lang/fi.json

plugins/CoreUpdater/lang/fr.json

plugins/CoreUpdater/lang/he.json

plugins/CoreUpdater/lang/hi.json

plugins/CoreUpdater/lang/hu.json

plugins/CoreUpdater/lang/id.json

plugins/CoreUpdater/lang/it.json