FIX: mbox import failed if no tags were configured

FIX: mbox import failed if no tags were configured

diff --git a/script/import_scripts/mbox/support/settings.rb b/script/import_scripts/mbox/support/settings.rb
index 9311dff..e1fd15b 100644
--- a/script/import_scripts/mbox/support/settings.rb
+++ b/script/import_scripts/mbox/support/settings.rb
@@ -40,8 +40,8 @@ module ImportScripts::Mbox
       @automatically_remove_list_name_prefix = yaml['automatically_remove_list_name_prefix']
       @show_trimmed_content = yaml['show_trimmed_content']
 
+      @tags = []
       if yaml['tags'].present?
-        @tags = []
         yaml['tags'].each do |tag_name, value|
           prefixes = Regexp.union(value).source
           @tags << {

GitHub sha: 739430c0