Disable vanishing option when logged out (commons-app#6135)

Author: savsch

app/src/main/java/fr/free/nrw/commons/settings/SettingsFragment.kt

@@ -272,6 +272,7 @@ class SettingsFragment : PreferenceFragmentCompat() {
             findPreference<Preference>("managed_exif_tags")?.isEnabled = false
             findPreference<Preference>("openDocumentPhotoPickerPref")?.isEnabled = false
             findPreference<Preference>("inAppCameraLocationPref")?.isEnabled = false
+            findPreference<Preference>("vanishAccount")?.isEnabled = false
         }
     }