Prune translations for strings that no longer exist

src/i18n/strings/kab.json

@@ -61,7 +61,6 @@
     "Update": "Leqqem",
     "Restart": "Ales tanekra",
     "Font size": "Tuɣzi n tsefsit",
-    "Custom font size": "Tiddi n tsefsit yugnen",
     "Decline": "Agwi",
     "Accept": "Qbel",
     "or": "neɣ",
@@ -437,7 +436,6 @@
     "What's new?": "D acu-t umaynut?",
     "Upgrade your %(brand)s": "Leqqem %(brand)s inek/inem",
     "A new version of %(brand)s is available!": "Lqem amaynut n %(brand)s yella!",
-    "You: %(message)s": "Kečč/kemm: %(message)s",
     "There was an error joining the room": "Tella-d tuccḍa deg unekcum ɣer texxamt",
     "Sorry, your homeserver is too old to participate in this room.": "Suref-aɣ, asebter-ik/im agejdan d aqbur aṭas akken ad yettekki deg texxamt-a.",
     "Please contact your homeserver administrator.": "Ttxil-k/m nermes anedbal-ik/im n usebter agejdan.",