Make page.title conditional in <h1>

- Fix mmistakes#312

_layouts/single.html

@@ -26,7 +26,7 @@
     <div class="page__inner-wrap">
       {% unless page.header.overlay_color or page.header.overlay_image %}
         <header>
-          <h1 class="page__title" itemprop="headline">{{ page.title | markdownify | remove: "<p>" | remove: "</p>" }}</h1>
+          {% if page.title %}<h1 class="page__title" itemprop="headline">{{ page.title | markdownify | remove: "<p>" | remove: "</p>" }}</h1>{% endif %}
           {% if page.read_time %}
             <p class="page__meta"><i class="fa fa-clock-o" aria-hidden="true"></i> {% include read-time.html %}</p>
           {% endif %}