added secure_url to og_image

rowers/templates/show_graph.html

@@ -10,6 +10,7 @@
 {{ workout.date }} - {{ workout.distance }}m - {{ workout.duration |durationprint:"%H:%M:%S.%f" }}{% endblock %}
 {% block og_image %}
     <meta property="og:image" content="http://rowsandall.com/{{ graph.filename |spacetohtml }}" />
+    <meta property="og:image:secure_url" content="https://rowsandall.com/{{ graph.filename |spacetohtml }}" />
 {% endblock %}
 {% block content %}
     <h1>{{ workout.name }}</h1>

rowers/templates/workout_view.html

@@ -14,6 +14,7 @@
 {% block og_image %}
 {% for graph in graphs1 %}
     <meta property="og:image" content="http://rowsandall.com/{{ graph.filename |spacetohtml }}" />
+    <meta property="og:image:secure_url" content="https://rowsandall.com/{{ graph.filename |spacetohtml }}" />
 {% endfor %}
 {% endblock %}
 {% block image_src %}