fix: Fix tagline not showing without description defined

Author: DGCK81LNN

lib/jekyll-seo-tag/drop.rb

@@ -75,7 +75,7 @@ def title
         @title ||= begin
           if site_title && page_title != site_title
             page_title + TITLE_SEPARATOR + site_title
-          elsif site_description && site_title
+          elsif site_tagline_or_description && site_title
             site_title + TITLE_SEPARATOR + site_tagline_or_description
           else
             page_title || site_title