FIX: Don't optimize icons during db:migrate when restoring backup

Uploads are extracted after the DB migration, so this could lead to a failure during the restore. Site icons get optimized after extracting uploads.

lib/backup_restore/database_restorer.rb

@@ -134,7 +134,7 @@ module BackupRestore
       log "Migrating the database..."
 
       log Discourse::Utils.execute_command(
-        { "SKIP_POST_DEPLOYMENT_MIGRATIONS" => "0" },
+        { "SKIP_POST_DEPLOYMENT_MIGRATIONS" => "0", "SKIP_OPTIMIZE_ICONS" => "1" },
         "rake db:migrate",
         failure_message: "Failed to migrate database.",
         chdir: Rails.root

lib/tasks/db.rake

@@ -77,7 +77,7 @@ task 'db:migrate' => ['load_config', 'environment', 'set_locale'] do |_, args|
 
   SeedFu.seed(DiscoursePluginRegistry.seed_paths)
 
-  if !Discourse.skip_post_deployment_migrations?
+  if !Discourse.skip_post_deployment_migrations? && ENV['SKIP_OPTIMIZE_ICONS'] != '1'
     puts
     print "Optimizing site icons... "
     SiteIconManager.ensure_optimized!

spec/lib/backup_restore/database_restorer_spec.rb

@@ -37,6 +37,7 @@ describe BackupRestore::DatabaseRestorer do
   def expect_db_migrate
     Discourse::Utils.expects(:execute_command).with do |env, command, options|
       env["SKIP_POST_DEPLOYMENT_MIGRATIONS"] == "0" &&
+        env["SKIP_OPTIMIZE_ICONS"] == "1" &&
         command == "rake db:migrate" &&
         options[:chdir] == Rails.root
     end.once