chore: Add BETA warning to multi accounts

assets/l10n/intl_de.arb

@@ -2580,7 +2580,7 @@
   "@addToSpace": {},
   "serverRequiresEmail": "Dieser Server muss deine E-Mail-Adresse für die Registrierung überprüfen.",
   "@serverRequiresEmail": {},
-  "enableMultiAccounts": "Aktiviere Multi-Accounts für dieses Gerät",
+  "enableMultiAccounts": "(BETA) Aktiviere Multi-Accounts für dieses Gerät",
   "@enableMultiAccounts": {},
   "bundleName": "Name des Bundles",
   "@bundleName": {},

assets/l10n/intl_en.arb

@@ -1567,7 +1567,7 @@
   "addToBundle": "Add to bundle",
   "removeFromBundle": "Remove from this bundle",
   "bundleName": "Bundle name",
-  "enableMultiAccounts": "Enable multi accounts on this device",
+  "enableMultiAccounts": "(BETA) Enable multi accounts on this device",
   "openInMaps": "Open in maps",
   "@openInMaps": {
     "type": "text",