Merge pull request creativecommons#571 from creativecommons/og-image-fix-quotes

Author: zackkrida

themes/vocabulary_theme/templates/macros/og_image.html

@@ -15,7 +15,7 @@
     {% if author and author.md5_hashed_email %}
       {% set gravatarURL = 'https://secure.gravatar.com/avatar/' + author.md5_hashed_email + '?size=300&d=mp' %}
       {% set queryParams = queryParams + '&images=' + gravatarURL %}
-      {% set pageTitle = page.title + '<br><sm style="font-size:70px;">By '+ render_author_name(author) + '</sm>'  %}
+      {% set pageTitle = page.title + "<br><sm style='font-size:70px;'>By " + render_author_name(author) + "</sm>"  %}
     {% endif  %}
   {% endif %}