Fix migrating from upstream to glitch-soc messing with hide_notifications mute settings (#2164)

db/migrate/20170914032032_default_existing_mutes_to_hiding_notifications.rb

@@ -1,8 +1,13 @@
+# frozen_string_literal: true
+
+# This migration is glitch-soc-only because mutes were originally developed in
+# glitch-soc and the default value changed when submitting the code upstream.
+
+# This migration originally changed existing values to `true`, but this has
+# been dropped as to not cause issues when migrating from upstream.
+
 class DefaultExistingMutesToHidingNotifications < ActiveRecord::Migration[5.1]
   def up
     change_column_default :mutes, :hide_notifications, from: false, to: true
-
-    # Unfortunately if this is applied sometime after the one to add the table we lose some data, so this is irreversible.
-    Mute.update_all(hide_notifications: true)
   end
 end