Handle no contribution link (#104)

Co-authored-by: Maciej Olko <[email protected]>

Author: StanFromIreland

template.html.jinja

@@ -24,7 +24,11 @@ main | <a href="metadata.html" target="_self">meta</a>
 {% for project in completion_progress | sort(attribute='completion,translators.number') | reverse %}
 <tr>
   <td data-label="language">
-    <a href="{{ project.contribution_link }}">{{ project.language.name }} ({{ project.language.code }})</a>
+    {% if project.contribution_link %}
+      <a href="{{ project.contribution_link }}">{{ project.language.name }} ({{ project.language.code }})</a>
+    {% else %}
+      {{ project.language.name }} ({{ project.language.code }})
+    {% endif %}
   </td>
   <td data-label="build">
     {% if project.in_switcher %}