Update ja.i18n.json
Update ja.i18n.json

Fix context that does not make sense.
nishimaki10/Rocket.Chat,fatihwk/Rocket.Chat,subesokun/Rocket.Chat,4thParty/Rocket.Chat,nishimaki10/Rocket.Chat,flaviogrossi/Rocket.Chat,fatihwk/Rocket.Chat,Sing-Li/Rocket.Chat,inoio/Rocket.Chat,inoio/Rocket.Chat,nishimaki10/Rocket.Chat,nishimaki10/Rocket.Chat,VoiSmart/Rocket.Chat,fatihwk/Rocket.Chat,pkgodara/Rocket.Chat,VoiSmart/Rocket.Chat,subesokun/Rocket.Chat,pkgodara/Rocket.Chat,pkgodara/Rocket.Chat,pkgodara/Rocket.Chat,VoiSmart/Rocket.Chat,Sing-Li/Rocket.Chat,4thParty/Rocket.Chat,flaviogrossi/Rocket.Chat,4thParty/Rocket.Chat,subesokun/Rocket.Chat,fatihwk/Rocket.Chat,Sing-Li/Rocket.Chat,subesokun/Rocket.Chat,Sing-Li/Rocket.Chat,flaviogrossi/Rocket.Chat,4thParty/Rocket.Chat,flaviogrossi/Rocket.Chat,inoio/Rocket.Chat